Added email obfuscation to admin.js

custom_css.php
added code to find the include path if the plugin is not in the usual location

particiants_database.php
all shortcodes are now processed though one function
added print_shortcode() method to handle all shortcodes
process_form() method fixed so POST arrays without certain valid elements are ignored
allowed extensions test is now tolerant of dots in the definition string
minor improvement to logo glyph in plugin listing

pdb-list-detailed.php
setting liks is now explicit about testing for a valid linkable URL

pdb-single-bootstrap.php
pdb-single-default.php
both use new group class value, add class to groups with all empty values

PDb_Base class
set_filter() method now ignores the plugin prefix if it is included in the filter slug

PDb_Form_Element class
dropdown, select and radio values can now have links placed on them

PDb_List_Admin class
search/sort dropdowns now include the field name if the title is the same as another field.

PDb_List_Query class
shortcode filters can now be used on link elements (was broken because the value is stored as an array)

PDb_Settings class
_get_identifier_columns() result is now cached

PDb_Shortcode class
Groups will all empty fields are now given a class

PDb_Signup class
email receipt error handling now looks for invalid email address

PDb_Template_Item class
add class property and print method

xnau_utility.css
improved selector for glyph font

git-svn-id: https://plugins.svn.wordpress.org/participants-database/trunk@962796 b8457f37-d9ea-0310-8a92-e5e31aec5664