Created exceptions for all cases
Added ScriptBox element

ScriptBox() class added for customization template page
Added some extra logging for flash messages
Added page_controls_exist() method
Simple docs fix
Added entire suite of page models for PXE

* PXEServer()
* CustomizationTemplate()
* SystemImageType()
Intersphinx support, local rtd docs theme
Added tests for PXE

* Added PXE Server CRUD tests
* Added Customization Template CRUD tests
* Added System Image Type CRUD tests
* Added RHEL template file
lazycache is easier to read, doesn't eat docstrings
Merge pull request #620 from seandst/intersphinx

Intersphinx support, local rtd docs theme
Merge pull request #621 from seandst/lazycache

lazycache is easier to read, doesn't eat docstrings
Stop generating sphinx warnings if a lazycache has no docstring
Merge pull request #624 from seandst/lazycache

Stop generating sphinx warnings if a lazycache has no docstring
Merge pull request #615 from psav/pxe_objects_and_tests

PXE objects and tests
Merge pull request #623 from psav/exceptions

Created exceptions for all cases