Added file.close().
Moved the sequence-related function to its own extension.
Merge branch 'master' of https://github.com/practicalswift/Pythonic.swift

# By practicalswift
# Via practicalswift
* 'master' of https://github.com/practicalswift/Pythonic.swift:
  Minor cleanups.
  Updated documentation.
  Added another Set test case.
  Removed import from usage example.
  Added Set usage examples.
  Added tests for Set(…).
  Using let instead of var where possible.
  Using Set() for the empty set instead of Set([]).
Specified "Swift.Collection" as protocol for Set to avoid build error in Xcode.

Specifically "'Collection' is ambiguous for type lookup in this context"
Added support for comparing tuples of 2 or 3 items.
Added str.partition.
Merge branch 'master' of https://github.com/practicalswift/Pythonic.swift

# By practicalswift
# Via practicalswift
* 'master' of https://github.com/practicalswift/Pythonic.swift:
  Line length tweaks.
  Improved code readability by adjusting line length.
  Backing dict is now Dictionary<T, Bool>() instead of Dictionary<T, T>().
  Started implementing RegularExpressionMatch.

Conflicts:
	src/Pythonic.set.swift
Merge pull request #6 from kareman/master

Added str.partition, support for comparing tuples of 2 or 3 items, and file.close().