Issue #3028771 by shaal, Not Real, pawandubey, kjay, smaz, Eli-T: Add some missing RTL css for the umami demo

Issue #3027236 by rachel_norfolk, kjay, tonypaulbarker, akshay_d, shaal, Eli-T, Not Real, babusaheb.vikas: Umami - hero block is identical on Home and Recipe pages, so potentially confusing

Issue #2915673 by borisson_, alexpott, Gábor Hojtsy: Ignore coding standards in sites/* PHP files as they are for configuration and not real code

Issue #2468045 by Lendude, vaplas, geertvd, tim.plunkett, dawehner, xjm, cilefen, catch, Berdir, alexpott: When deleting a content type field, users do not realize the related View also is deleted

Revert "Issue #2468045 by Lendude, geertvd, vaplas, tim.plunkett, dawehner, xjm, cilefen, Berdir, catch: When deleting a content type field, users do not realize the related View also is deleted"

This reverts commit 917ed83e.

Issue #2468045 by Lendude, geertvd, vaplas, tim.plunkett, dawehner, xjm, cilefen, Berdir, catch: When deleting a content type field, users do not realize the related View also is deleted

- Patch #952772 by oriol_e9g, mdupont, bleen18, idflood: theme_html_tag() optional value not really optional.

- Patch #768490 by JohnAlbin, sign: theme_table_select_header_cell() is not really a theme function.

- Patch #18418 by chx: jonbob node_access_view_all patch changed the return value of node_access_where_sql to empty which breaks nicely all queries which are still using this function. This is a good incentive to upgrade to db_rewrite_sql, yes, but I think it causes confusion, 'cos it is not really trivial why the query suddenly not works. Let's make it trivial -- rename it _node_access_where_sql, it is no longer a function to be called from outside. node_access_join_sql similarly.

- Added "custom" date/time format... to allow user-timezone-adjusted custom date formats. I didn't add special logic to translate parts of it, but it's not really needed, as this is only meant for internal usage (e.g. checking if timestamp A is on the same date as timestamp B).
  Some modules (such as diary) should be changed to take advantage of this function, as they are now still using GMT+0 dates in some cases (e.g. the recent diary entries box).

Commiting my work of last Sunday:

 - removed ban.inc and ban.module and integrated it in account.module
   under the name "access control" --> the ban code was not really up
   to standard so this has now been dealt with.  This refactoring and
   reintegration cuts down the code size with 100 lines too.  :-)
   (The ban.module code was really old and it showed.)

 - added node.module and made the other modules reuse some of this
   code --> cut down the code size of modules by at least 100 lines
   and adds stability.

 - added a status() function to admin.php to display a conform status
   message where appropriate.  See admin.php for usage.

 - removed $theme->control() and made comments.inc handle this itself
   wrapped in a $theme->box().  No need to clutter the themes with
   such complexity --> updated all themes already. :-)

 - some small visual changes to some administration pages to be more
   consistent across different modules.