Add better Python 3 support

This adds Python 3 support without relying on 2to3. This allows for
easier testing on Python 3.3.
Remove unused imports
Use locale.getpreferredencoding()
Merge pull request #17 from myint/python3

Add native Python 3 support
Revert "Remove Travis status"

This reverts commit bef18e00dad30093a21051b46e8d6b3a961b7938.
Sanitize output wrt COMP_WORDBREAKS (fixes repeat completions containing a colon); filter readline completions
Fix tests
Deactivate action upon successful parse if its pattern is not open. Fixes #16.
Set COMP_WORDBREAKS as required by 632dc9a6474b353bfbec34b66f27f02a944e9cc3
Merge pull request #19 from jimparis/master

Set COMP_WORDBREAKS in the per-app hook too
Give exclusive control over completions to actions that are unsatisfied. Fixes #16 (for real this time)
Fix logic for some types of actions
Add and document argcomplete.warn()
Formatting
v0.3.8
Flush previous completions only for optionals. Need to think more about when to do the same for positionals.
Return from lexer instead of quitting if EOF is found. Fixes #21
v0.3.9
Only mark argparse as required for versions of Python without argparse

Conditionally include argparse as a requirement only for versions of
Python that do not have argparse already bundled.
Merge pull request #23 from kfdm/argparse-requirements-fix

Only mark argparse as required for versions of Python without argparse