Improve translation of "Edit block" message

This allows, for instance, to reverse the order of words.
Removed unused variables and outdated comments
Simplify call to getValue when called with 2 parameters

If func_num_args() is 2 then we can avoid call_user_func_array
and call $av->getValue() directly (that's faster)
make area name translatable
Fix outdated cache after saving tracking codes
class added to login form

it's a bit tricky to style the login form since we don't have a
class. This PR adds a class, no sure about the official name
conventions here but it makes styling much easier.
fix mixin call

the order of the parameters is wrong
https://github.com/concrete5/concrete5/blob/master/web/concrete/css/ccm_app/twitter_bootstrap/mixins.less#L139
class for "forgot password" form
Let's deprecate BLOCK_NOT_AVAILABLE_TEXT

This define contains a localized text to be shown when a block is no
longer available.
Let's deprecate it since:
1. after calling Localization::changeLocale() this define contains a text
in the wrong language.
2. there's no reason to have manage this text represented with a define
whereas all the other messages are represented directly
User selector update to make it clearable

Made the single user selector clearable to make it consistent with the multi user selector and the image selector.  Also fixed a problem with only one ccm_triggerSelectUser ever being accepted.  If you passed in a custom javascript function it would either never be used it or only be used for all user selector instances on the page.

To illustrate the problem:

$user_selector->selectUser('field1');
$user_selector->selectUser('field2',null,'doSomething');

the old generated javascript:

user selector 1: 
ccm_triggerSelectUser = function(uID, uName, uEmail) {
   …
}

user selector 2:
ccm_triggerSelectUser = function(uID, uName, uEmail) {
	doSomething(uID, uName);
}

ccm_triggerSelectUser has been overwritten at the window level, the first triggerSelectUser will never get called.
Updated attribute key insert id 

When using the mysqli adodb driver (which I use for transactional
 support), you can't have any queries between an insertion and a request for
 the insert id or adodb will return 0.
disable notices for missing en_US translations
Illegal Job run duration causes a database exception

Fixes bug report:
http://www.concrete5.org/developers/bugs/5-6-2-1/illegal-job-run-duration-causes-a-database-exception/
Fix comments and user messages
Add some more space to "Keywords" search field

# Widen the space available for the Keywords search field.
# To not make the Search button fall over the "Advanced Search" button
  pull the whole form down a bit
Add some more space to "Keywords" search field

# Widen the space available for the Keywords search field.
# To not make the Search button fall over the "Advanced Search" button
  pull the whole form down a bit
# Make the space for Group field as wide as the Set field of file manager
# Show "Advanced Search" instead of "Advanced" in link that shows Advanced
  search criteria
Translate all the system page names

The page names that need to be translated are the ones that
have isSystemPage() == 1, not only those that have
isAdminArea() == true (the first include the second)
Localize dates in job list
Allow changing only the case of user names

Currently, if you try to change only the case of a username (for instance,
from admin to Admin), you'll receive the error message "The username '%s'
already exists".
With this edit we'll let changing the case.

As a further minor improvement, the check if the username is unique is
done only if the username changes (before it was always performed).
Add translation in dashboard full-sitemap
Stacks or Trash is not true in isAdminArea, but need translated.