Apply Android Studio and Lint inspections

* Remove always true/false/null parameters
* Remove pointless bitwise expressions
* Remove pointless boolean expressions
* Remove unnecessary continue statements
* Convert fields to local variables
* Remove unused resources
Add scrollable widget

Closes #21
Update translations

* Slovenian (damir12)
* Russian (Doodlez)
Merge widgets together, bump version

* Allows for seamless upgrade to scrollable widget
Tap task on widget to open task edit screen
Complete tasks from scrolling widget
Update Slovenian (damir12)
Update to JDK 1.7
Show recently completed tasks on widget
Better progress bar for syncing

Made changes so that a progress bar cannot jump back (especially while
syncing) and changed the way synchronising code presents progress so
that it appears more representative.

Closes #46
Fix sqlite overflow on backup import

This is a hack to prevent the widget from generating a huge sqlite query
when it receives a flood of data source changed notifications. Not sure
why it was happening so this needs to be revisited
Remove updates table
Remove reengagement service, update translations

* Slovenian (damir12)
Remove public and readonly columns from tasks
Dont save voice input attachment on quick add

Closes #4
Remove attachment download
Enable custom filters
Remove menu items preference screen
Update task list activity menu

* Fix search menu missing from action bar
* Remove unused icons
Add billing permission for donations