Add "Assigned To" and other fields to ticket export

Addresses #589
Only set "ft" field if requested

The "ft" field does not exist when the attachment migration takes place.
Therefore, attachment migration will fail because the records cannot be
inserted into the database due to the missing "ft" field.
Crypto wrapper - implements tag based en/decryption
Crypto wrapper - implements tag based en/decryption
Properly escape text/plain email bodies

If there characters in the plain text body of the email that appear like
HTML tags, for instance

From: <sip:527772432@172.18.0.2>;tag=952422a9dd1ap1a6o1

The <sip...> part would be removed by the Format::striptags() call in
Format::sanitize().
Assume text from the web user interface is not html
Add documentation for the crypto process
Merge remote branch 'jared/feature/crypto' into feature/crypto
Refactor logic'

Conflicts:
	include/class.crypto.php
Add nolint to obvious false positives
Ensure cookie path is set for the session cookie
* Scan for inline attachments
Incoming messages with empty body and an inline attachment might not have
parts - depending on encoding used.

* Use "-" tag for emails with empty body/message
Refactor PHPSECLIB Crypto
Add test function - basic testing (will be replaced by real test suit)
Add a test suite for the crypto libraries

Only use 8 bytes (64-bits) for the IV data (salt) for the encryption keys,
except for Mcrypt, which requires you to query the specific length and use
it specifically.
Move getCipher to base class
Add cipher validator - checks to make sure the cipher is valid & available.
Merge remote branch 'jared/feature/crypto' into feature/crypto
Revert back to using cipher specific iv len
Remove temp. password
Merge pull request #646 from greezybacon/issue/assigned-to-export

Add "Assigned To" and other fields to ticket export

Reviewed-By: Peter Rotich <peter@osticket.com>
Merge pull request #648 from greezybacon/issue/647

Only set "ft" field if requested

Reviewed-By: Peter Rotich <peter@osticket.com>
Merge pull request #652 from greezybacon/issue/htmlchars

Properly escape HTML chars in text/plain email bodies

Reviewed-By: Peter Rotich <peter@osticket.com>