Fix test-mode

When running as non-root, mongrel2 attempts to run in a test-mode.
Some recent enhancements to the chroot and daemonize code broke that.
Update links to tarball for 1.9.0
Bump version number
Merge branch 'release/v1.9.1' into develop
Delete gcov files more selectively.

Previously, make target 'clean' would delete all '*.gc*' files, this would
erroneously delete 'src/polarssl/tests/suites/test_suite_cipher.gcm.data'.

This contributed to marking the src/polarssl submodule dirty and caused
polarssl's test suite to fail.

Now it deletes only '*.gcno' and '*.gcda' files.
Merge pull request #216 from cpick/delgcov

Delete gcov files more selectively.
Case insensive match on websocket upgrade

IE 10 and 11 send "Websocket" rather than "websocket" which is allowed
by the specification.
Clean up preparation and testing of src/polarssl git submodule
o Move all submodule preparatory scripting inline so it is visible
o Support multiple versions of polarssl, by providing version specific
   patch files for their src/polarssl/include/polarssl/config.h
o Support patch for PolarSSL 1.3.4, in preparation for future support
o Improve tests/cert_tests.c to detect an invalid tests/ca/m2-cert.pem,
  and adjust its certificate validation expectations accordingly,
  while ensuring that the maintainer is warned to update the cert.
o Fix tests/runtests.sh to allow passage of stderr output to maintainer
Restore execution of submodule init, and deinit submodule in 'make pristine'
Compatibility with older (eg. mac) sed