Fix for meta refresh tags

Meta refresh tags with an interval (regardless of how great) were still
being redirected automatically.  Also, a meta refresh with the URL
specified as the same (current) URL would result in an endless refresh -
some checks added.

Created an additional PhpBrowser config var 'refresh_max_interval' to
control the largest interval allowed for an auto redirect.

Created a new test case, and added to a couple existing test cases.

NOTE: I didn't create an 'issue' for this - I thought I read somewhere that an issue should be created first so I was doing that... if you require an issue created please let me know and I'll do so.

NOTE2: I changed some of the code style to be a bit more PSR-2 compliant (simpler if() statement) but feel free to throw that back at me.

NOTE3: I also prefer seeing variables initialized in higher scopes (applies to $match variables I'm using) again feel free to throw back at me.

Enjoy!