Merged charset declarations of global_charset_info.h and charset_info.h into charset.h header file.
After that I needed to remove global_charset_info.h and charset_info.h header declarations from all the drizzle code base. I wrote a script that search for global_charset_info.h in all the source code files and replace it with charset.h if that file does not already have charset.h header declaration otherwise it just remove global_charset_info.h from that particular file. I wrote a smilar scrpt for replacing charset_info.h with charset.h. I then restructured charset.h in order to make it more structural. i.e All the extern declarations are consolidated together one after the other. Similar pattern has been followed for struct declarations and functions in the charset.h header file