Add license notice

Author: rohanrhu

THIRDPARTYLICENSES

@@ -0,0 +1,4 @@
+Ace Editor: frontend/thirdparty/ace - frontend/thirdparty/ace.LICENSE
+Xterm.js: frontend/thirdparty/xterm - frontend/thirdparty/xtermjs.LICENSE
+SourceSansPro: frontend/thirdparty/sourcesanspro - frontend/thirdparty/sourcesanspro/OFL.txt
+icofont: frontend/thirdparty/icofont - frontend/thirdparty/icofont.LICENSE

frontend/components/AboutDialog/html/AboutDialog.html

@@ -58,6 +58,9 @@
                                 <div class="AboutDialog_licenses_license">
                                     Ace Editor: frontend/thirdparty/ace - frontend/thirdparty/ace.LICENSE
                                 </div>
+                                <div class="AboutDialog_licenses_license">
+                                    Xterm.js: frontend/thirdparty/xterm - frontend/thirdparty/xtermjs.LICENSE
+                                </div>
                                 <div class="AboutDialog_licenses_license">
                                     SourceSansPro: frontend/thirdparty/sourcesanspro - frontend/thirdparty/sourcesanspro/OFL.txt
                                 </div>

frontend/thirdparty/ace/LICENSE

@@ -0,0 +1,25 @@
+
+Copyright (c) 2010, Ajax.org B.V.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of Ajax.org B.V. nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

frontend/thirdparty/xtermjs.LICENSE

@@ -0,0 +1,21 @@
+Copyright (c) 2017-2019, The xterm.js authors (https://github.com/xtermjs/xterm.js)
+Copyright (c) 2014-2016, SourceLair Private Company (https://www.sourcelair.com)
+Copyright (c) 2012-2013, Christopher Jeffrey (https://github.com/chjj/)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.