add config option for shell prompt regex

~/.saga.cfg now accepts:

[saga.utils.pty]
prompt_pattern      = [\$#%>\]]\s*$

This hopefully advances #340
Differentiate between DONE and FAILED.
fix typo -- thanks Mehdi!
Merge branch 'devel' of github.com:radical-cybertools/saga-python into devel
Proper state checking and general unpbssifying.
Merge branch 'devel' of https://github.com/saga-project/saga-python into devel
fix problems on colored grep
Merge branch 'devel' of github.com:radical-cybertools/saga-python into devel
more thorough fix for all usages of grep
A check added to prevent infinite loop while detecting shell prompt. A line of code uncommented to avoid preventing shell prompt ref #340
Merge pull request #343 from mehdix/devel

An infinite loop prevention and shell prompt fix regarding #340