Ticket #2 (new enhancement)

Description

Event flow:

1. System starts up and reads its configuration from configuration files in such order:
   • system-wide configuration file ('/etc/rwt/config.py')
   • user configuration file ('$HOME/.rwt/config.py')
   • project configuration file ( '$cwd/rwt-config.py')
   • command line options
2. If a random seed is specified, System initializes pseudo random numbers generator from it. Otherwise, it initializes from system time.
3. System sets starting web page as the current one.
4. System performs the following procedure for the current web page:
   1. if current page is a link, download the page content; otherwise (a form) - download an HTTP POST result
   2. if the output contains a text, satisfying any error regexp, notify the user and stop the execution
   3. get all links and all forms from the page
   4. limit the links and form actions set to those satisfying allowed url regexps
   5. select random link or form and set it as the current one
   6. if the current page is a form post, generate the random input to it using configured generators
   7. log the action as an executable python code
   8. repead the step
5. System continues the previous cycle until the earlies happen: the time limit would be reached or the number of links tranversed would be exceeded.

Tests:

1. System-wide configuration file doesn't exist
2. System-wide configuration file is not a valid python script
3. User configuration file doesn't exist
4. User configuration file is not a valid python script
5. Project configuration file doesn't exist
6. Project configuration file is not a valid python script
7. Command line option is broken (define CLI syntax!)
8. Random seed is not a number
9. A page (through a link) is unavailable (returns anything bug 2* or 3* HTTP code)
10. A page (through an HTTP POST) is unavailable
11. No error regexps.
12. Invalid error regexp (e.g. not a regexp at all)
13. No links and no forms on the page (define behaviour! e.g. return to the previous page and select another link)
14. No links on the page.
15. No forms on the page.
16. Generator for a form field is not available.
17. Generator for a form field throws an exception.
18. Time limit is not a number
19. Tranversed links limit is not a number.
20. Success test of a simple local website.
21. Success test of text generator
22. Success test of radiobutton generator
23. Success test of select generator
24. Success test of checkbox generator
25. Success test of textarea generator
26. Success test of date generator