Go back to Shell script for provision

Shell scripts have a more compact syntax.  Also try to install packages
with the same package manager at once, to avoid superfluous process
executions and dependency calculations.
Fix PHP test cases

Get comments right
Improve handling of process working directory in checkdoc
[Fix #73] Do not set buffer-file-name to nil

Doing so apparently breaks (checkdoc-current-buffer), so just fall back
to the name of the temporary file.  This causes bogus warnings again,
bug at least doesn't cause the checker to fail.

See bbatsov/prelude#259
Add issue references to test case
Explain guarded use of define-fringe-bitmap
[Fix #71] Add phpcs checker

Thank you, @steckerhalter.