Added completion file for Maven
add todo.txt-cli as a plugin

Since it is referenced in the default .bash_profile and in aliases and
themes, why not make it an official plugin?

This creates a 'todo/' directory in /plugins/available, and installs
todo.sh and friends there.  Tab completion and the 't' alias should work
out of the box.

Note: it was also necessary to modify .gitignore to ignore the files
todo.sh generates in custom/.
Merge branch 'master' into todo.sh
respect profile overrides

overrides may now be specified for any of these defaults:
TODO_DIR=$BASH_IT/custom    # change if you want todo.txt and friends
                            # to live somewhere else

TODOTXT_DEFAULT_ACTION=ls   # change if you want a different action,
                            # like 'lsp' or 'lsprj'

TODO_SRC_DIR=
$BASH_IT/plugins/available/todo  # for custom installs with plugins
conditionally define t()

if user has installed the todo plugin, forego defining the 'one thing'
todo function t().
conditionally define t()

if user has enabled the todo plugin, skip defining the 'one thing'
todo function t().
Extended enable/disable and describe functionality to work for aliases and completions as well.
Changed meta info resolution to look for data based on the type, e.g. about-plugin, about-alias, about-completion.
Cleaned up parameters and added meta data for plumbing functions.
add alias metadata, remove help()
alias-help()
Updated help
Merged @erichs changes for the bash-it function.
update README
Merge pull request #3 from erichs/enable-disable-aliases-completions

readme update
Added alias for Growl notification, can be used like the following to notify once the long running process (make in this example) is done:
$ make install ; grnot
Added comment for grnot.
Don't require tmux server to be running for completion to work.
Merge remote-tracking branch 'von/master'
Merge pull request #139 from nwinkler/enable-disable-aliases-completions

Enable/Disable for aliases and completions