Merge branch '4087_verilog_syntax_highlighting'

Merge branch '4087_verilog_syntax_highlighting'

* 4087_verilog_syntax_highlighting:
  verilog syntax: clarify that also refers to systemverilog,
  verilog syntax: added some missing operators
  verilog syntax: reorganized and added missing compiler directives
  verilog syntax: reorganized and added missing system tasks and system functions
  verilog syntax: added IEEE1800-2009 and 2012 missing keywords
  verilog syntax: added IEEE1800-2005 missing keywords
  verilog syntax: added IEEE1364-2005 missing keywords
  verilog syntax: added IEEE1364-2001 missing keywords
  verilog syntax: added missing ieee1364-1995 keywords
  Ticket #4087: verilog syntax: removing keyboards attribute, endattribute, strength