Drawer submenu capability.
MainDrawer submenu implementation.

temp. commit
Make ViewPager update it's fragments of period change.
Fix snap-positions.
BarChart empty and loading states.
Add stability.
BarChart refactor.
Make drawer subitems and parent items highlight correctly.
Focus on last selected period when returning to reports.
fixed reports and pager to integrate with previous content
Merge pull request #413 from toggl/taavirehemagi-reports-monthyear

taavirehemagi-reports-monthyear. Closes #402
ViewReport pattern added
updated project list styles
Piechart tap fixed
piechart tap refresh list correctly
Merge pull request #419 from toggl/anton-androiduifixes

Improve speed and styles on report's ListView and PieChart
PieChart animation enabled
UI tweaks and fixes.
PieChart refactor.
text size was too big.