simplify the command-line api

[nicks]

I remembered why I wanted this! It makes things a lot easier to read and to type. xargs + find isn't a good solution, because it's non-portable (find works slightly differently on different unixes)

There are 3 major changes here:

• support for file globs
• support for -O=ADVANCED
• support for -W=VERBOSE

Based on feedback from the last PR, I added better docs on how to use this, and got rid of the gcc-style O=2

[MatrixFrog]

Actually if you have five keys or less you can just use .of() instead of the builder: http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/collect/ImmutableMap.html#of(K, V)

so in this case:

    ImmutableMap.of(
        "QUIET", WarningLevel.QUIET,
        "DEFAULT", WarningLevel.DEFAULT,
        "VERBOSE", WarningLevel.VERBOSE);

[nicks]

done

[ChadKillingsworth]

With this new version, I have no objections.

[concavelenz]

I'm fine with this.