Count and print the number of correct statements

[jnidzwetzki]

In the current version of pgspot, only the number of statements with the states error, warning, and unknown are counted and shown. It might be helpful for the user to see how many statements were successfully processed by pgspot.

To give the user the information that pgspot has actually performed an analysis of the input file (i.e., the file is not empty and pgspot recognized the contained statements), the status output could be enhanced and include the number of correct statements:

Errors: 0 Warnings: 0 Unknown: 0 Correct: 103