pfSense

Mount image rw during changes

Cleanup the tab format of the system user/group/server management pages.
The edges were square instead of rounded like most pfSense pages. Also
make sure tabs and cancel buttons are present in the add privilege and
add certificate pages.

Cleanup authentication code. The basic auth method, the passwd, htpasswd
and pam backing functions have been removed. The basic auth method was
legacy code and the backing functions were redundant with no added value
that I could see. A simplified replacement backing function named...

Rewrite the pfsense privilege system with the following goals in mind ...

1) Redefine page privileges to not use static urls
2) Accurate generation of privilege definitions from source
3) Merging the user and group privileges into a single set
4) Allow any privilege to be added to users or groups w/ inheritance...