Merge pull request #36 from RomanovRoman/gulp

handle proxy error
fix deps bug
"backbone-mixin": "~0.3.5",
"sp-utils-bootstrapmodal": "~0.1.1"
add choose for sass and scss syntax
fix bug with load tasks problem
fix issue #19 fix revision problem of extra files
Add gulp: sprite generator solves #35
process only local fonts
no need to filter files, process only local fonts
fix clean task
update deps
fix environment errors
add support of svg sprites
fix list generation
fix postss for dev mode