refactor ktest
Fixed issue #91. Java VM arguments: Implemented support for environment variable K_OPTS where we can specify java virtual machine arguments. On all K tools on all platforms. Tested on windows and linux. If not specified default values are used. Implemented a relevant help message as part of krun --X, or other <tool> --X message.
Colors: Improved color matching algorithm for terminals. Now more cells should be colored. Added a new krun option: terminal-color, to specify the background color of the terminal.
Ugly fix for LTL model checker.
lots of restructuring of examples and tests for them under 1_simple
updating README and config.xml
updated SIMPE exercises and corresponding config.xml and README files
updated main config.xml
Merge branch 'master' of https://github.com/kframework/k