[Tizen] Polish Python code according to Chromium Python style guidelines.

Per Chromium Python style guidelines,
http://www.chromium.org/chromium-os/python-style-guidelines
This CL sets single quote for string values, and sets functions names
with CapWords() style.
[Tizen] Enable pkginfo uninstall for Tizen.

This CL supports to uninstall package information from Tizen Database,
as well as remove application icons, execute path and XML file from Tizen system.

As for the python script arguments, the --install option will not take
values any more, also a new option --uninstall is added to support
uninstall package information from Tizen.

For class InstallHelper() in Python, the parameter input_path is removed from
constructor, because it could be generated by the other parameters.
Also several class member variables are added, e.g, icon_path_ , execute_path_,
which could be shared by install and uninstall functions.

Besides, we found the issue that application icon could not display on home
screen if package name contains white spaces. To fix this issue, the installer
script strips these whitespaces when writing package information into database.