v4 patches

#597 Adds class `weekend`
#569 Added pointer cursor css to input button
#554 Adds option `dayViewHeaderFormat`
#283 Added Clear button and SideBySide fix
#141 Added Today button and SideBySide fix

#Breaking!
Renamed `bootstrap-datetimepicker.less` to
`_bootstrap-datetimepicker.less` to prevent LESS compilers from
generating an extra CSS file

#Other
Added support for moment 2.4.8 `LTS` format
Removed check for LF line breaks in jslint (silly windows)