fix(Security): enable CSRF cookie based authentication

 Add a Spring Security filter to set a cookie with the CSRF token generated by Spring.
 Configure $http service to read the CSRF token form the cookie and put it in a header known by Spring

 linked to #363
test(AuthenticationSharedService): with CSFR logout call is a POST
fix(Swagger): add CSFR token to request
fix(Security): enable CSRF cookie based authentication

 Add a Spring Security filter to set a cookie with the CSRF token generated by Spring.
 Configure $http service to read the CSRF token form the cookie and put it in a header known by Spring

 linked to #363
fix(Swagger): add CSFR token to request
fix(Security): enable CSRF for cookie based authentication in V2

 Add a Spring Security filter to set a cookie with the CSRF token generated by Spring.
 Configure $http service to read the CSRF token form the cookie and put it in a header known by Spring

 linked to #363
fix(Security): send CSRF cookie on token change only
Merge branch 'I#363_EnableCSRF' of https://github.com/tgillieron/generator-jhipster into I#363_EnableCSRF

Conflicts:
	app/index.js
	app/templates/src/main/java/package/web/filter/_CsrfTokenGeneratorFilter.java
	app/templates/src/main/webapp/scripts/_app.js
	app/templates/src/main/webapp/scripts/_services.js
	app/templates/src/test/javascript/spec/_servicesSpec.js
fix(CSRF): remove cookie after logout
fix(Security): remove scripts and html from spring security filter chain
fix(CSRF): remove cookie after logout
fix(Navigation): in $rootScope.back() go to 'home' if previous state do not exist
style(Generator): add indent
refacto(CSRF): rename filter class and variables
Enabling snapshot plugins for spring-plugin-milestone

Fixing issue https://github.com/jhipster/generator-jhipster/issues/829 where a new machine without the RC2 version of the plugin cannot resolve the maven dependency.
fix(Grunt): package external css

add custom step to usemin:css flow to allow packaging of custom and  external CSS in one file while being able to run the autoprefixer task
Make grunt hot reload .js files again

grunt didn't watch js files in the new modular frontend this fix makes js hot reload working again.
Comment was duplicated. A new comment about the ribbon was added
Merge pull request #838 from henri-tremblay/duplicate-browser-prompt

Comment was duplicated. A new comment about the ribbon was added
Save the changelog so we can overwrite it when the file is re-generated