Simplified Makefile.PL since several module dependencies are now optional
Refactored many things; made some dependencies optional

All tests pass
Rewrote tests to use HTTP::Tiny instead of WWW::Mechanize

HTTP::Tiny is in the core in modern Perls; in older ones there's
a fat chance some other module has required it already. Even if not,
it may be that the RPC::ExtDirect::Server will come along with ::Client,
which will bring in HTTP::Tiny anyhoo.
Update Makefile.PL with (build) HTTP::Tiny dependency
Added tests for If-Modified-Since; fixed a bug caught by the tests
Added exlib (extra libs) to .gitignore
Added tests for CGI::Simple detection/defaulting
Added a test for 403 on URIs starting with dots
Modified .. matching regex
Split CGI::Simple and cgi_class into separate test files
Added tests for custom URI handlers
More logging made optional
Added tests for optional MIME modules; fixed some bugs caught by the tests