[Extensions] Decouple the FunctionHandler from the Internal Extension Context

This is the first step for removing the InternalExtension class. The idea here
is to delegate the wrapping of callback ids to the FunctionHandler and make
it optional using composition.
[Extensions] Convert the parameters of the function handlers into a struct

The previous syntax was too verbose and now with the struct, adding
a new parameter won't cause a mass rename.
[Extensions] Remove the InternalExtension class

All the functionality was moved tho the ExtensionFunctionHandler and
can be optionally used via composition.
Bump version to 1.29.11.0
Merge pull request #520 from tmpsantos/internal_extensions_refactoring

Internal Extensions Refactoring
Bump version to 1.29.12.0
[Tools] Adjust increment-version.py's style to Google's.

In other words, replace unix_style_functions() with CamelCased() ones.
Merge pull request #818 from rakuco/fix-increment-version-style

[Tools] Adjust increment-version.py's style to Google's.
Bump version to 2.31.0.0

This is based on Chromium 31.0.1650.11.
Build fixes based on patches by Caio Marcelo.