avoid using sed with -i flag

-i is GNU sed specific, instead use a temporary file. Also changed the
 sed expression to an inversion print because it's (supposedly) faster
quiet and config options

[-q|--quiet] wd will not print any messages (except for help and
list).

[-c|--config] <file> will use the specified <file> as config instead of
the default `~/.warprc`. This is useful for testing and allow users to
specify an alternative config file in their setup.
add some basic tests

using shUnit2 for shell script testing
add version tracking

current version can be printed with [-v|--version]
formatting
exit with proper exit codes

exit with status 1 on failures and warnings, 0 otherwise
minor clean up
test duplicates, name validity and removal
Added `wd ls` test
add man page
install man page through install script
Cleanup warp points

Remove warp points with nonexistent directories
fixes #12 - better `wd show` output
fixes #9 - prefix all variables
add debug flag

using [-d|--debug] will cause wd to exit with an exit code, which is
needed when testing
minor clean up
fixes #11 - optional argument to `show`

passing an argument to show will look up any point with the given name
add show argument to completions
Fixes #13 - Document new features in v0.4

(show, --version, --config, --debug, --quiet)
Merge branch 'patch-1' of github.com:sergey-kucher/wd into 0.4-wip

Conflicts:
	wd.sh