[#73183568]update default.html

import docs.min.css
add code sample in current components.html

Navs, Navbar, Breadcrumb, Pagination
update Gruntfile

- add new task "multi-select" to copy files of "Bootstrap Multiselect" plugin
 - http://davidstutz.github.io/bootstrap-multiselect/
[#73183568add]update dropdowns

- add code sample for each patterns
- add new dropdown pattern which is combined with input elements
  - for this pattern, uses plugins
    - Bootstrap Multiselect  http://davidstutz.github.io/bootstrap-multiselect/
[#73270894]add buttons dropdowns

create new section "Buttons Dropdowns" which contains 4 patterns below:
 - Single button dropdowns
 - Split button dropdowns
 - Sizing
 - Dropup variation

update "_buttons.scss" to tweak sizes of buttons

remove unnecessary css file "bootstrap-glyphicons.css"
remove 'console.log' in main.js

- 'console.log' is only for debug
tweak style of 'search'box in dropdonws

change 'width' of search box in the dropdowns which uses 3rd party plugin for implementation.
Merge branch '73183568add-dropdown' of github.com:gengo/style-guide into 73270894buttons-dropdown
format scss files below,  via csscomb

- _button.scss
- _dropdowns.scss
- docs.scss
format scss files below , by using SassBeautify

- scss/_buttons.scss
- scss/_dropdowns.scss
- scss/docs.scss

SassBeautify is plugin for sublime text
https://sublime.wbond.net/packages/SassBeautify
add new sass variable

also format '_variable.scss' by using SassBeautify
apply sass variable '$dropdown-border-radius' in some property
'$dropdown-border-radius' is used in '_dropdown.scss'
change format in several scss files
- change indent level from '4' spaces to '2' spaces
- scss/_buttons.scss
- scss/_dropdowns.scss
- scss/docs.scss
revert 'scss/_variable.scss'
fix conflict in merge

fix 3 conflicts in merge with master

- scss/_dropdowns.scss
- scss/_buttons.scss
- Gruntfile.coffee
fix scsslint error

modify 3 scss files
- scss/_buttons.scss
- scss/_dropdowns.scss
- scss/docs.scss
Merge b96473b92b9881a5a01611a5782dfb0bebd34039 into 1089329180042eac583086916b382980ec9c2c35
Travis build 63