Make test suite pass on OS X

The [home] key appears to be system-dependent--on OS X (and possibly
other systems?) it is bound to beginning-of-buffer instead of
beginning-of-line by default, causing a test that uses it to fail.
mark `company-complete-number` for repeat by change (fix #414)
require `evil-core` in `evil-search` (fix #415)
Implement q/ and q? for editing searches (fixes #292)
merge request 66
add Emanuel Evans to authors list
remove check for ! argument in ex completion (fix #407)

This check in `evil-ex-command-completion-at-point` is not necessary,
because the bang is part of the command itself and is handled
appropriately when building the completion tables.