Add .gitignore

Taken from  https://github.com/github/gitignore
cosmetic changes (indentation)
BitParser: use intptr_t where appropriate

intptr_t is an integer type capable of holding a pointer

error: cast from ‘unsigned char*’ to ‘unsigned int’ loses precision [-fpermissive]
BitParser: use min<int> where appropriate

error: no matching function for call to ‘min(int, long int)
cosmetic changes: translate a comment
Compile using the 2011 ISO C++ standard
cosmetic changes: fix misspells and typos in comments
Test with smaller intervals

ulimit for the stack size is 8192 KBs on Fedora 18 x86_64, so intervals
of 4 MBs should be safe.
Don't be lazy and allocate only what's needed.
Use numeric_limits for the predefined run of 1s
refactoring: renamed BYTES_PARSED to PARSED_CHARS
Rename *.h to *.hpp

Related: http://stackoverflow.com/questions/152555/h-or-hpp-for-your-class-definitions
Makefile: remove cruf & add dependencies
Cleanup README and convert it to Markdown
README: add description in English