samurai 0.3

New features

• Add -d explain option to explain why outputs get rebuilt.

Bug fixes

• Fix escaping of paths containing '.
• Fix some incompatibilities with ninja related to newline and comment parsing.
• Write output of failed jobs, even if console is currently in use.

Cleanups

• Use custom binary search tree implementation instead of search.h, simplifying code and removing dependency on XSI.
• Specialize hashtable for string keys, simplifying implementation.