MAJOR Ability to use several working directories.

Changes:
 -- added ability to use several working directories separated by ';'
 symbol (like in Windows 'PATH' variable;
 -- adjusted validation - now we will fail if any of specified directories
 does not exists;
 -- increased log detalisation a bit.
DOC Added examples of new 'workDir' syntax.
DOC Added description of new 'workDir' syntax.
DOC Built-in 'help' is much more brief now.
MINOR Version++.