Added 'useCRLF' option

[evergreen-lee-campbell]

Added a 'useCRLF' option to prevent a new linefeed appearing every time the gulp task is run on Windows machines.

Resolves #42

[coveralls]

Coverage decreased (-0.6%) to 97.484% when pulling fab0d05 on evergreen-lee-campbell:master into 38e66fd on VFK:master.

[VFK]

@evergreen-lee-campbell Thank you for your contribution.
I really can't reproduce #42 I created test files with Windows Notepad and Sublime Text with "windows line endings" options and no matter how many times i run this plugin i don't see additional linefeeds. Maybe i'm doing something wrong though so i guess we can do something like your PR. But i have some questions:

1. If the whole difference is that one \r in regex, could something like this:

/(\r?\n?)([ \t]*)(<!--\s*build:(\w+(?:-\w+)*)\s*-->)\n?([\s\S]*?)\n?(<!--\s*endbuild\s*-->)\n?/ig

or

/(\n?|\r\n?)([ \t]*)(<!--\s*build:(\w+(?:-\w+)*)\s*-->)\n?([\s\S]*?)\n?(<!--\s*endbuild\s*-->)\n?/ig

just work without any new config options? Could you test it please?
2. Could you change tabs to 4 spaces please? Formatting is pretty broken.

[UncleBill]

I like this option. And I already use @evergreen-lee-campbell 's repository in my package.json.

[aschekatihin]

Notepad and sublime aren't attempting to do line endings normalization and basically ok with mixed LF and CRLF in one file. But if one using Visual Studio or there is a git autocrlf then there is an extra lines problem.

Regexp that solved problem for me:
var regex = /(\n|\r\n)?([ \t]*)(<!--\s*build:(\w+(?:-\w+)*)\s*-->)([\s\S]*?)(<!--\s*endbuild\s*-->)(\n|\r\n)?/ig;

[chaijunkun]

I have tried, modified my local dependent version as what @evergreen-lee-campbell committed. it works fine! why @VFK doesn't merge it to master and release it?

[chaijunkun]

I wrote a test case project as below:
https://github.com/chaijunkun/gulp_test

1. npm install
   2.npm test

template file is from src/index.html, and output file is dist/index.html.
in macOS, there will be two 0x0a (s) between the two tags:

endbuild
build:seg_2

but in Windows, the character 0x0a presents 3 times between the two tags.