rebase
custom files can now be imported on the web interface
Merge pull request #60 from yushan87/bug-fix

custom files can now be imported on the web interface
Fixed facility arugment item type error, fixed getTrueVarExp not providing a math type, added copy ability to ProgramStringExp
Merge pull request #61 from bdurkee/master

Fixes for facilities
fixed bugs in math type checking
Merge pull request #62 from bdurkee/master

fixed bugs in math type checking