Cordova framework integration, Android support, mobile UI & options tab

Cordova integration and android platform :
- Added cordova directory with required config
- Added cordova applications generation in gulpfile
- Added cordova development instructions
- Used cordova plugins to simulate missing chrome api  plugins (chrome.serial and chrome.fileSystem)
- Added cordova clipboard support
- Added android operating system and Cordova gui mode
- Fixed some css and js files to make them working on Android as well as on computers
- Added --skipdep argument to accelerate cordova build (gulp task)
- Added a webview helper to help people to update the webview app of their device

New options tab :
- Added options tab replacing the options dropdown
- Added option to switch between phones UI and computers UI

Mobile interface and global interface improvements :
- Simplified the structure of the header with flex css
- Made headerbar and tab container responsive (compact headerbar and side menu)
- All tabs are adapted to mobile interface (except firmware flasher)
- The servos and adjustments tabs are not fully adapted but are "usable"
- Improved header bar animation
- Improved log expandation animation
- Added swipe gesture to toggle side menu

Fixes during the development :
- Logo position
- Dark mode
- Auto connection
- Error messages (cordova_chromeapi.js)
- Responsive grid
- Testing
- Disconnection
- Width of boxes inside the OSD tab
- Fixed cli tab
- OSD tab
- Motor stop switch
- White spaces in boxes
- Dialogs size
- Connect button state
- Prevent tablet with a height larger than 575px to switch to computers ui
- Fixed logging tab
- Fixed code smell
- Fixed yarn cordova plugin install issue
- Fixed content_wrapper
- Fixed vibrations when scrolling
- Fixed scrolling bar alignment
- Fixed dialogReportProblem height
- Fixed rates logo
- Fixed auto connection default value (true)
- Fixed D to D max
- Fixed dialogs

Added required messages in locales/en/messages.json file


Required changes

Changed build alias name to betaflight
Splitted main_cordova.html to a css and a js file
Changed values which are automatically change by gulp tasks in cordova/package.json and cordova/config.xml
Fixed code smells


Fixed code smells


Changed cordova plugins url


Changed release.keystore

Author: WalcoFPV

.gitignore

@@ -13,6 +13,13 @@ debug/
 release/
 testresults/
 
+# Cordova
+cordova/www/
+cordova/platforms/
+cordova/plugins/
+cordova/resources/
+cordova/package-lock.json
+
 # OSX
 .DS_store
 

README.md

@@ -48,14 +48,15 @@ Unstable testing versions of the lates builds of the configurator for most platf
 
 **Be aware that these versions are intended for testing / feedback only, and may be buggy or broken, and can cause flight controller settings to be corrupted. Caution is advised when using these versions.**
 
-## Native app build via NW.js
+## Native app build via NW.js (windows/linux/macos) or Cordova (android)
 
 ### Development
 
 1. Install node.js (version 10 required)
 2. Install yarn: `npm install yarn -g`
-3. Change to project folder and run `yarn install`.
-4. Run `yarn start`.
+3. (For Android platform only) Install Java JDK 8, Gradle and Android Studio (Android SDK at least level 19)
+4. Change to project folder and run `yarn install`.
+5. Run `yarn start`.
 
 ### Running tests
 
@@ -69,12 +70,14 @@ yarn gulp <taskname> [[platform] [platform] ...]
 ```
 
 List of possible values of `<task-name>`:
-* **dist** copies all the JS and CSS files in the `./dist` folder.
+* **dist** copies all the JS and CSS files in the `./dist` folder [2].
 * **apps** builds the apps in the `./apps` folder [1].
-* **debug** builds debug version of the apps in the `./debug` folder [1].
+* **debug** builds debug version of the apps in the `./debug` folder [1][3].
 * **release** zips up the apps into individual archives in the `./release` folder [1]. 
 
 [1] Running this task on macOS or Linux requires Wine, since it's needed to set the icon for the Windows app (build for specific platform to avoid errors).
+[2] For Android platform, **dist** task will generate the `./cordova` folder
+[3] For Android platform, you need to configure an emulator or to plug an Android device with USB debugging enabled
 
 #### Build or release app for one specific platform
 To build or release only for one specific platform you can append the plaform after the `task-name`.
@@ -84,6 +87,7 @@ If no platform is provided, all the platforms will be done in sequence.
 * **Linux** use `yarn gulp <task-name> --linux64`
 * **Windows** use `yarn gulp <task-name> --win32`
 * **ChromeOS** use `yarn gulp <task-name> --chromeos`
+* **Android** use `yarn gulp <task-name> --android`
 
 You can also use multiple platforms e.g. `yarn gulp <taskname> --osx64 --linux64`.