Split off the constants and verifier into their own PHP files.
Split the widget into its own file.
Move the options related code into browserid_options.php
Lots of extraction.

* Create lots of lib/browserid-*.php functions to take functionality away from the main browserid.php
lots of extract methods on the initialization functions
Update function names to better convey their meaning
set dev version number to v0.46
Remove the default password nag screen if registering with BrowserID.

Other cleanup.
Add a general and advanced setting tab to the settings page.
Splitting off the options into general and advanced pages.
More cleanup of the options.
capitalize 'post' in 'Post comment'
Merge branch 'extract-classes'