Verbose option argument

[Leont]

Module::Build accepts just about any argument convention under the rainbow in an unpleasantly heuristic and opportunistic manner. To be more precise it will accept any of:

1. verbose=1
2. --verbose
3. --verbose 1
4. --verbose=1
5. --no-verbose
6. --noverbose
7. --no_verbose

Getopt::Long (and other parsers AFAIK) can only parse some of those, in three different ways but never more than half at the same time.

1. As a boolean option (verbose!) it can parse 2, 5 and 6
2. As an integer option with mandatory argument (verbose=i) it can parse 3 and 4
3. As an integer option with an optional argument (verbose:1) it can parse 2, 3 and 4

Module::Build::Tiny does the last possibility currently, which I consider the most backwards compatible option as it makes the common styles 2 and 3 DWIM. Other than style 1 (which we don't support anyway), I don't think I've seen any of the others in the wild (5-7 would be silly anyway).