fix(datepicker): remove edge case position updates

Closes #1296
1. Added filter that converts string to Date object.
2. Added relevant tests.
Applied JSHint fixes.
1. Added stringtodate module.
2. Added stringToDateFilter to datepicker as a dependency.
Merge branch 'datepicker_patch' of github.com:dnasir/bootstrap into datepicker_patch

Conflicts:
	src/datepicker/datepicker.js