Introduce hidden options

Developers often use hidden options for internal purposes which they
do not wish to expose to end-users.
support for option of type InetAddress
Added PathOptionHandler for automatic parsing of Path objects in java 7
Added MultiFileOptionHandler and MultiPathOptionHandler to take a single argument and parse several File or Path objects from each (respectively)
Removed the coding that was not compliant with -source 1.5 in the unit tests
Git Ignore Idea
Improving the doc
fixed up the code. Now I feel a little better.
Fix ARGS4J-25 - support args like "-coll val1 val2 -coll val3" with `@Option(handler = StringArrayOptionHandler.class, …)`

Fix `java.lang.IllegalArgumentException: array element type mismatch`
Revisted ARGS4J-25 patch.

StringArrayOptionHandler shouldn't batch up tokens into a single array and use Setter<String[]>.
The Setter abstraction is designed to work with individual items, in this case String.
See RestOfArgumentsHandler as an example.

With this change, the modification in ArrayFieldSetter made in the previous commit becomes unnecessary.
doc clarification
Merge pull request #26 from cyrille-leclerc/git-ignore

Git Ignore .idea folder
Merge pull request #21 from dlad/inetaddress

Support for option of type InetAddress
code should still run on Java6
doc improvements
TAB -> WS
Merge tag 'pull-23'
opening this up for subtypes to better control visibility
Massaged the contribution from @andrewgaul.

The hidden() switch that always hides it from the usage screen is pointless, as it can be trivially achieved by not writing any usage. I think the underlying issue the change was trying to address is that being able to show different subset of options is often useful. Such a use case can be already seen in ExampleMode.

In this change, I introduced a generalized version of ExampleMode called OptionHandlerFilter, which allows the caller to specify the subset of options. The printUsage method is extended to support this parameter, and in this way the caller can control the subset of options to print them.
Merge branch 'pull-20'

Conflicts:
	args4j/src/org/kohsuke/args4j/CmdLineParser.java