New languages, some bugfixes, enhanced theme customizer

• Added: EnlighterJS v3.3.0
• Added: EnlighterJS Theme-Customizer v2.2.0
• Added: compatbility mode for CodeColorer . features requested by ajtruckle on GitHub
• Added: filters to alter the editor config (Gutenberg+TinyMCE) - features requested by ajtruckle on GitHub
• Added: documentation how to use external themes (linked within contextual help)
• Changed: external themes requires enlighterjs as css dependency to avoid styling issues
• Changed: removed Enlighter version string from external themes
• Bugfix: added missing languages to the list (abap,scala,qml,verilog)
• Added: apachehttpd/htaccess support
• Added: lighttpd support
• Added: nginx support
• Added: purebasic support - thanks to gphilippot on GitHub
• Added: minimal latex/tex support
• Changed: theme font sizes + line-height are based on relative em values - only the font size of the outer wrapper is set explicitly
• Changed: removed "function" highlighting regex from sql
• Added: option to customize the raw code pane
• Added: option to set the token base styles inlcuding font-size - feature requested on GitHub
• Added: option to set button background-color and line-height
• Added: tab defaults to change global settings
• Changed: moved button related settings to tab buttons
• Changed: moved line-number settings to tab lines
• Changed: removed tab "fonts"
• Bugfix: highlighted-line hover selector was invalid -> selection of background-color:hover was not possible - thanks to ajtruckle on GitHub #4
• Bugfix: removed typos in code edit dialog - thanks to ajtruckle on GitHub