Fix pathing issues on Windows

[bejado]

Fix Path::split, Path::isAbsolute, Path::getParent, and getCanonicalPath on Windows.

Fixes #13
Fixes #14

Some edge-case windows pathing may still not work:

• "drive relative" paths: "C:tmp.txt"
• UNC paths (network paths): "\foo\bar" (will be collapsed to \foo\bar, which may resolve to a different location than expected)
• "absolute paths": "\foo\bar" (may or may not resolve to drive root)

[bejado]

Changed line endings to UNIX style, hence the massive diff. New function at the very bottom: Path::isAbsolute