Math highlighting with + prefix.
Fixes:
* Modifications to allow @ and $ in literals (though not as the first character!)
* Changed function of verb argument in RPLError
* RPLError can now show all information independantly.
* Actual error thrown for bad struct names.
* Prettied up some errors in rpl.py
* Can now clone clones, fixing a bug in data exporting.
* Literals can no longer parse escape sequences. They were never supposed to accept them in the first place. (Will have to adjust __unicode__ for them later.)
* Fixed bug in RPL data exports causing some commas not to be written.
* Added explicit format key to data and format structs.
* Format key now accepts a prefix to the imported keys in the form [@format0, prefix]
** Note that it does properly splice the x so it's xprefixkey. It also updates refs.
* Some fixes dealing with end form in data xkey formats.
* Bugs regarding cloning and exporting fixed in data struct.
* format.format actually usable now.
* data/format docs now explain "expand"
* Removed useless Format.basic
* Updated calc struct to reflect changes to literal. Much nicer imo.
* data tests made much more robust.
* Tests suite now normalizes newlines.