Added generic and mysql UNION tests from 1 to 25 columns.

Adapted config file and command line removing now outdated --union-test switch.
Minor bug fix.
Minor code refactoring.
Got rid of some debug messages, standardized logging of UNION tests.

sqlmap.conf

@@ -251,19 +251,15 @@ longestCommon = False
 # Default: 5
 timeSec = 5
 
-# Test for and use UNION query (inband) SQL injection.
-# Valid: True or False
-unionTest = False
-
 # Range of columns to test for
 # Valid: range of integers
-# Default: 1-20
-uCols = 1-20
+# Example: 1-10
+uCols = 
 
 # Character to use to bruteforce number of columns
 # Valid: string
-# Default: NULL
-uChar = NULL
+# Example: NULL
+uChar = 
 
 
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