adjustments to std.mem split / separate

* rename std.mem.split to std.mem.tokenize
 * add future deprecation notice to docs
 * (unrelated) add note to std.os.path.resolve docs
 * std.mem.separate - assert delimiter.len not zero
 * fix implementation of std.mem.separate to respect the delimiter
 * separate the two iterators to different structs
67bd45f0cfAndrew Kelley committed on 2/4/2019, 8:24:06 PMparentf44ce78
8 files changedLine totals unavailable