Fix rewrite_base

rewrite_base was broken because it uses -%> instead of %> so it
generated RewriteBase and RewriteCond on a single line. It's also
removed from the vhost since RewriteBase is only valid in a <Directory>
context.
make default mods configurable

...in a backwards-compatible manner.

Right now there are two options, either to enable a rather broad batch
of modules that someone found to be a good default set, or to leave them
unmanaged all-together.

This patch provides the users wtih the ability to manage their set of
default modules, by passing it as array to default_mods.

This fixes #298

n.b.: we've added test cases here, but they aren't yet part of the
actual test spec, because I have no idea how to do that.
Merge pull request #315 from blkperl/ruby19_fix

Fix a2mod ruby19 bug
Merge pull request #319 from blkperl/vhost_wsgi

Add WSGI params to apache::vhost
Merge pull request #307 from oxilion/remove-rewrite_base

Fix rewrite_base
Merge pull request #314 from igalic/default_modules

make default mods configurable
Add suphp mod