Fix link content duplication when links are embedded inside other links

When a link falls within another link, such as a URL string within a method call, processing both would result in the processed URL being appended to the processed method call, duplicating the text from the URL. Instead, keep track of the links processed, and ignore a link if it's inside of a previously processed link.

Here's a test case which illustrates the problem:

```objc
/**
`NSURL *baseURL = [NSURL URLWithString:@"http://example.com/v1/"]`
*/
@interface Fooclass : NSObject
@end
```

Result:

```html
<p><code>NSURL *baseURL = [NSURL URLWithString:@"http://example.com/v1/"]</code>http://example.com/v1/<code>"]</code></p>
```

With patch:
```html
<p><code>NSURL *baseURL = [NSURL URLWithString:@"http://example.com/v1/"]</code></p>
```

The test case does indeed cover this problem but certainly could be improved.
Merge pull request #359 from paulmelnikow/fix_urls_in_code_spans

Fix link content duplication when links are embedded inside other links
Test suite: Fix compilation error

The cast to `__va_list_tag *` fails with an error on my system (OS X 10.8.4, Xcode 4.6.3). I've tried several other possibilities and was unable to find a way to make the cast in a way that does build. So, I removed it, and suppressed the warning.

Faking out a va_list is kind of dirty to begin with, so I think suppressing this warning is okay.

If there's a better fix I'd be happy to use that instead!

```
GBObjectsAssertor.m:215:103: error: use of undeclared identifier '__va_list_tag'
                        [self assertCommentComponents:argument.argumentDescription matchesValues:firstExpectedComp values:(__va_list_tag *)argList];
                                                                                                                           ^
GBObjectsAssertor.m:215:118: error: expected expression
                        [self assertCommentComponents:argument.argumentDescription matchesValues:firstExpectedComp values:(__va_list_tag *)argList];
```
Fix array bounds crash in -processAvailabilityBlockInString

Fixes #349 and failing test case:
```
GBCommentsProcessorRegistrationsTesting
testProcessCommentWithContextStore_combinations_shouldRegisterMethodDescriptionBlock
```
docsetFeedFormats is not a string

Remove support for templates in `--docset-feed-formats` option, which is not necessary and does not work. Write a proper test case that does not crash. Fix compiler warnings on conversion of enum to id.
Fix crash when setting --xcrun-path or --docset-xml-filename

These items aren't properly capitalized by DDGetoptLongParser and result in a KVC exception.

This is a somewhat dirty way to handle this, but the other option I see is to rename the instance variables to use DDGetoptLongParser's capitalization, which doesn't seem better.
Apply recommended warnings for Xcode 4.6
Fix placeholder replacement test case
Merge pull request #360 from paulmelnikow/fix_test_case_build

Test suite: Fix compilation error
Merge pull request #361 from paulmelnikow/fix_tests

Fix failing test cases
Make 'comment found' entries log at INFO level
Merge pull request #364 from commandtab/make_comments_info

Make 'comment found' entries log at INFO level
Minor: Fix error in format string
Use +[NSNumber numberWithBool:] in place of GRYes
Minor: Fix type mismatch in format string
Minor: Use explicit type in format string
README: Homebrew no longer installs templates by default
GBCommentsProcessor: Convert GBCrossRefData to an object

This is with an eye toward converting to ARC, which does not like having NSObjects in structs, and also makes the code more readable.
Merge pull request #365 from paulmelnikow/minor_fixes

A few minor changes
Merge pull request #366 from paulmelnikow/gbcrossrefdata

GBCommentsProcessor: Convert GBCrossRefData to an object