fix issue #481
Merge pull request #483 from dwightguth/ltl

fix issue #481
Fixing issue #428.
   - errors found in VariableTypeInference were reported immediately instead being thrown further.
   - fixed some typos.
added Java implementation for builtin string ops: replace/replaceAll/replaceFirst/countOccurences
Adding regression test and fixing some inconsistencies in krun.
Merge pull request #486 from kframework/fix-is428-noparse

Fixing issue #428.
changed to use StringUtils in the implementations of replace/replaceAll/replaceFirst; added Javadoc
Merge pull request #487 from yilongli/fix-string-op-replaceAll

fixing issue #456
updated definitions and programs in prog-equiv
fixed some errors in config.xml in prog-equiv folders.
resoved config.xml conflict
fixed some errors in config.xml in prog-equiv folders.
fixed copyright and xml comments in config.xml files.
fixed *.out conflicts