Merge pull request #170 from zapion/v2.0

Add empty getLatestBuildId()
Refactoring the controllers of flash_pvt
Merge remote-tracking branch 'mozilla/v2.0' into v2.0

Conflicts:
	controller/base_controller.py
Merge pull request #171 from askeing/v2.0

Refactoring the controllers of flash_pvt
Refactoring the TK mode flash_pvt.
Load config from .flash_pvt file.
fix pep8
Merge pull request #172 from askeing/v2.0

Refactoring the TK mode flash_pvt.