Deleted Eclipse preferences.
can input a formula and generate a truth table for it
added a wff checker for the formula input and an error field for if they input something that is not a wff.
merged master into the branch
add column buton now works, also a target formula is shown
Merge branch 'master' into TruthTableBuilder3
columns are now buttons that can either be T or F, also started to try and get the columns to be evaluated
added constants to QButtonPanel
unicode
Added tests for QffWffChecker
minor updates to WffChecker and classes that extend it
Added Kekai's tests for QffWffChecker

* 'wffchecker-future' of ssh://github.com/PeterDrake/Logic:
  Added tests for QffWffChecker
added error field to buttonpanel, instead of in testButtons
finished merge from master
Updated QffWff test cases
Merge branch 'wffchecker-future' of ssh://github.com/PeterDrake/Logic into wffchecker-future
Merge branch 'wffchecker-future' into TruthTableBuilder3
qf grammar trench work
more test edits
Merge branch 'wffchecker-future' of ssh://github.com/PeterDrake/Logic into wffchecker-future

* 'wffchecker-future' of ssh://github.com/PeterDrake/Logic:
  more test edits
  Updated QffWff test cases