Added two check() functions to DtmcPrctlModelChecker that are to be called by the "outer world" that check a given formula and print the result the standard output.
Fixed bug in GmmxxDtmcPrctlModelChecker that prevented BiCGStab using ILU preconditioning from working
Refactored mrmc.cpp to remove larger code blocks from main().
Added option to specify logging file. If no file is set and the verbose option is not set either, logging is basically disabled by setting the logging level very high. This is a workaround for the fact that at least one log appender needs to be set in the logging framework, which would not be the case if both logging facilities (file and console) are disabled.