Change supported API level to 15+ (4.0.3+)

Google Keep is supported only by Ice Cream Sandwich
4.0.3+.
Set action bar color to blue
Add Android L style floating button

Android L style floating button is possible through the use
of FloatingActionButton (FAB) library.

https://github.com/FaizMalkani/FloatingActionButton

Tapping the floating button will open Google Keep if installed.

- Change Keep Trash background to pure White
- Add new custom made drawable for floating button
- Switch to FrameLayout

Signed-off-by: Shubhang Rathore <shubhang92@gmail.com>
Fix crash on tapping floating button if Google Keep is not installed

The user will be redirected to the Play store link of Google Keep
in case Google Keep is not installed.
Add logging to tapping on floating window
Implement hide and unhide of floating button on scrolling

Signed-off-by: Shubhang Rathore <shubhang92@gmail.com>
Add drawables of menu icons for note editor action bar
Add custom editor menu xmls for note editor action bar
Add few more drawables and resource xmls

For note editor action bar
Implement custom icon listing for note editor action bar

- Archive
- Show checkboxes
- Hide checkboxes

Above icons can be set to be shown or be hidden from the action
bar of the note editor screen in the official Google Keep app.

This customization can be achieved through checkboxes in
Keep Trash.

Signed-off-by: Shubhang Rathore <shubhang92@gmail.com>
Bump to version 1.2