Merge pull request #16 from miriammariety/master

Modified category window
added add item
Merge pull request #17 from xtianvortex/master

added add item
partial update commit, working on table
Merge branch 'master' of github.com:LucidComplex/inventory-system
testing table
added refresh to database
renamed some variables, added AddQuantityCommand (does not work)
renamed some variables, added AddQuantityCommand (does not work)
Merge branch 'master' of github.com:LucidComplex/inventory-system
fixed add quantity
partial commit
created workaround to update tables
partial commit
fixed project requirements
AddCategoryCommand
Edit UI