fix accordions and buttons, improve code quality - more info into the release note

Bug Fixes

• component:
  • accordion (388e0055)
  • disabled buttons (415de632)
• core:
  • clean notice.txt (f6cf52b7)
  • fix eslint warning (cf0d7ada)
  • fix glyphicons name for arrow next and previous (5b16999e)
  • fix css linting errors and eslint errors (8abe3aa1)
  • fix cssmap file who generate error onto chrome, update less and cssmin dependenc (2afd9c39)
  • IE8 sizes (b3664785)
  • remove icon-orange increment after file name for IE8 compatibility reasons (742539f0)
• doc:
  • add exception to htmllint (d18b06a4)
  • fix htmllint errors (654829e3)
  • put stable url into config file for download (770dc7e8)
  • orange panel (0e73269e)
• test: passing bs unit tests (2e2d2b2c)