BUG: Drop incorrect & useless query on client libraries info update

This commit fixes following error:

  SQL error in ClientLibrary::Save()():ERROR:  relation
  "client_site2library_id_seq" does not exist
Cosmetics: Simplify some if conditions

Unset variables is a subset of empty variables:

 !isset($var) == true  implies  empty($var) == true
 !empty($var) == true  implies  isset($var) == true

Thus,

 !isset($var) || empty($var)

could be simplified to:

 empty($var)

The patch is generated by:

 find . -type f -name '*.php' -exec sed -i 's/if(!isset($\([^)]*\)) || empty($\1)/if(empty($\1)/' '{}' \;
 find . -type f -name '*.php' -exec sed -i 's/if(empty($\([^)]*\)) || !isset($\1)/if(empty($\1)/' '{}' \;
 find . -type f -name '*.php' -exec sed -i 's/if(isset($\([^)]*\)) && !empty($\1)/if(!empty($\1)/' '{}' \;
 find . -type f -name '*.php' -exec sed -i 's/if(!empty($\([^)]*\)) && isset($\1)/if(!empty($\1)/' '{}' \;
BUG: Fix two typos in file viewer

This commit fixes following errors:

 PHP Notice:  Undefined variable: uploadFile in /var/www/cdash/viewFiles.php on line 65
 PHP Notice:  Trying to get property of non-object in /var/www/cdash/viewFiles.php on line 65
 PHP Notice:  Undefined variable: dbsize in /var/www/cdash/viewFiles.php on line 88
BUG: Fix a typo

This commit fixes the following error:

 PHP Notice:  Undefined variable: coveragestatus in
 /var/www/cdash/ajax/getviewcoverage.php on line 299
ENH: Support PostgreSQL in filter data functions

Tested-by: Nils Gladitz <nilsgladitz@gmail.com>
BUG: Don't display errors when project gets unselected on Edit Project page

Also rearrange some lines for better readability.