Get keys from json.colHeaders

Fixes an issue where columns of data are placed under the wrong column headers.  Using the column headers as the keys variable ensures that the order of columns is preserved.
Choose between icon sets for action buttons

icon.library allows specification of icon set.  Choose between Font Awesome and stock Bootstrap icons.
Updates actionButton manual

Adds description of the icon.library argument
Param description in function definition
Bug Fix in Font Awesome class
Fixes typo in a url
Install Instructions
Reword Install Instructions
Fixes issue with specifying single library
Icon library selection issue
change busyIndicator class to shiny-busy
hideshinyalert

Adds a function which hides a shinyalert.  Includes documentation.
Merge pull request #7 from dcurrier/master

Get keys from json.colHeaders