Resolve #16 - Secure LDAP connection

Implemented LDAPS connections (on both port 636 & 389).
Began larger refactoring of code by encapsulating LDAP
management into its own class. Also implemented a debug_log()
method to use for non-error log output.
Default cas include path inserted into databases

Resolved #44 - If the CAS Path is null or not setup, code looks for the
default path and if the file exists there it adds the path to the database and
populates the field in the form.
Merge pull request #48 from TriptiSharma/issue-44

Default cas include path inserted into databases
Merged current BellevueCollege code.

Also fixed invalid call to debug_log()
Fix invalid constant

Fixed a constant name change in ldapManager that didn't get
propagated to wordpress-cas-client.
Added new fields to register_settings

Resolved #49 - New fields like casserver, ldapuri were not being saved
since they were not being added to the options list for single site.
Refactored to include logic from commit 64373b3

Commit 64373b3 (pull request #42) broke my current changes for
Issue #16 so in order to resolve the conflicts, I'm merging LDAP
functionality that was added into the ldapManager class.
Moved string literal to a constant.
LDAP Password Encrypted

Resolved #39
Encrypted LDAP password before it gets stored in the database.
Decrypt password after retreiving from database.
Password can be reset but its never visible to the user.
Migrated LDAP functionality into class

Moved majority of LDAP settings and functionality into
ldapManager class.
Added timestamp to debug log.
Merge branch 'issue-49' of https://github.com/TriptiSharma/wordpress-cas-client into issue-16
Merge branch 'issue-39' of https://github.com/TriptiSharma/wordpress-cas-client into issue-16

Conflicts:
	wordpress-cas-client.php
Added '@' to mcrypt function calls

Did this to inhibit display of warning messages in the UI.
Merge branch 'dev' of github.com:BellevueCollege/wordpress-cas-client into issue-16

Conflicts:
	wordpress-cas-client.php
Merge pull request #45 from TriptiSharma/issue-39

Pre-Test:
The following conditions were tested:

* Verify that the password is never exposed to the user
* Verify that the reset button provides a field to enter the password
* Verify that the password is stored in the database
Merge pull request #50 from TriptiSharma/issue-49

All fields on the CAS Client form were tested and verified against the database. The only field that is currently on the form that is not being saved is E-mail suffix but that was not part of the task
Merge branch 'issue-16' into dev
Merge branch 'dev' of github.com:BellevueCollege/wordpress-cas-client into dev
Merge branch 'issue-16' of https://github.com/shawn-bellevuecollege/wordpress-cas-client into shawn-bellevuecollege-issue-16