Add gitignore file
Merge pull request #40 from devurandom/feature/gitignore

Add gitignore file
Fixes an error with -pedantic -std=c99 and GCC 4.7.2: ‘visibility’ attribute ignored on types
Fixes a bunch of errors with -pedantic -std=c99 and GCC 4.7.2: ISO C restricts enumerator values to range of ‘int’
Amend dd1a18149cac29a69a0242a5efc467498f5f05cd: Visibility attribute is needed for MSVC/C++