Adds public functions to App object:

[tonybarbieri]

show_save_as_dlg
show_change_version_dlg
can_save_as

These are useful for calling outside of the App itself.

Necessary for shotgunsoftware/tk-multi-snapshot#6

[tonybarbieri]

If pull request #12 is accepted, the can_save_as public function is no longer needed.

-tony

[alandann]

Hey Tony,

We're having issues pulling in your changes - it's probably because it's taken me a month to get to them :(

Has anything changed with your repo that might stop us having access?

Thanks
Alan

[tonybarbieri]

Hrm...No nothing should have changed.

[tonybarbieri]

Is it because mine is still set to private?

[alandann]

Possibly - although Manne was able to pull some of your changes in before..

[alandann]

...he isn't able to with these now though!

[tonybarbieri]

Let me make them public. It might be because the shotgun repos went public but the forked repos havent :).

[tonybarbieri]

It is now public! Does it work?

[alandann]

It does indeed - thanks Tony - I may have some questions while I go through these......

[tonybarbieri]

Please feel free to hit me up!

[alandann]

Done! - will release shortly...

Thanks again for this Tony :)
Alan