Add a .toEscapedXML() method in Verb.java

The .toXML() method doesn't escape the verb body by default (which it
should). However, for backwards compatibility, keep the behavior of the
old method the same and add a new method that does this for you.
Changel twiml response example to use .toEscapedXML()

User the safer method instead of .toXML()
only set the request account sid on list loaded objects if it wasn't previously set
better generics for ListResource
Merge pull request #111 from juggernaut/xml-escaping

Add a .toEscapedXML() method in Verb.java
Fix Account getSid
kill intellij dropping
Merge pull request #123 from twilio/account-sid

Make Account.getSid() just return the sid property directly
Use getSid() instead of getRequestAccountSid() for Account.getResourceLocation
Merge pull request #124 from twilio/account-sid-again

Use getSid instead of getRequestAccountSid for Account.getResourceLocation
Merge pull request #122 from codylerum/118_try2

only set the request account sid on ListResource loaded objects if it
wasn't previously set
Update UsageRecord unit getters to match API property names
Merge pull request #125 from twilio/update-usage-properties

Update UsageRecord unit getters to match API property names
Add Cody Lerum to AUTHORS
Bump to 3.4.2
[maven-release-plugin] prepare release twilio-java-sdk-3.4.2
[maven-release-plugin] prepare for next development iteration
add missing UsageCategory and return null if not found
better coverage for UsageCategory
add reference to transcriptions/recordings from call