[WIP] Remove old c style casts

The Apple clang 4.0 seems to include Wold-style-cast in Weverything.
A lot of old c style casts like ```(int)var``` resides in CppUTest, producing Wold-style-cast.
Since Werror is given, CppUTest cannot be built on at least my Mac OS X Mavericks.

To remove Wold-style-cast, the old c style casts should be replaced with c++ style casts like ```static_cast<int>(var)```.
Renewing existing casts is a hard task because there is no way to do automatically.
Therefore, please tell me whether this casting renewal is acceptable.

Thanks.