[patch] Implement AccountManagerPlugin Jira authentication support

This is tacked now with #8791 for AcctMgr directly. Patch welcome.

Test and comment on the new patch, please. Thank you in advance.

(In [10492]) AccountManagerPlugin: Add sha512 hash type support for HtPasswdStore files, refs #5464 and #8791.

Python2.5 or later is strictly required to use sha512 algo, error implemented for older versions. New htpasswd_hash_type is sha512 with common hash identifier $6$ (see http://wiki.call-cc.org/eggref/4/crypt for details). Last but not least a unit test extension of test_create_hash for the new hash type is provided too.

I'm rolling this now against the lack of feedback so far, still any test report is highly appreciated.

(In [10523]) AccountManagerPlugin: Forget about pure sha512, refs #5464, #8791 and #8933.

sha512_crypt is the module, which we need for conformant hash calculation. However, this is not a Python standard, so try to import from passlib and fallback to crypt as last resort, if this is capable at all.

(In [12398]) AccountManagerPlugin: Releasing version 0.4, pushing development to acct_mgr-0.5dev.

Availability of that code as stable release closes #874, #3459, #4677, #5295, #5691, #6616, #7577, #8076, #8685, #8770, #8791, #8990, #9052, #9079, #9090, #9139, #9246, #9252, #9547, #9618, #9676, #9843, #9852, #9940, #10023, #10028, #10123, #10142, #10204, #10276, #10397, #10412, #10594, #10625 and #10644.

Some more issues have been worked-on, yet without confirmed resolution, refs #5464 (for JiraToTracIntegration), #8927 and #10134.

And finally there are some issues and enhancement requests showing progress, but known to require more work to resolve them satisfactorily, refs #843, #1600, #5964, #8217, #8933.

Thanks to all contributors and followers, that enabled and encouraged a good portion of this development work.