Fix parsing makefile options

Ignore-this: 5a78d517f4b5855aabbbcd4e54f0a257

When searching for libraries (the '-l' prefix), it incorrectly processed
input in case it contained "-L/usr/lib/x86_64-linux-gnu", for example

darcs-hash:20140730141144-56b4d-88979159617e6983ff7691881fb7e88b350234b7
Update build dependencies on Install.windows

Ignore-this: bf9cc849ed7bdc855520f33dfed7d492

darcs-hash:20140730155042-56b4d-14c6127cceefd2ef72e5d1e346d89c2326e8b461
Updated Windows installation instructions

Ignore-this: 73965cb66c31be257c2b8b7795a4dc57

darcs-hash:20140731144344-56b4d-e50e2d7eed447559f3017328852413524c1e12a7