Update ycm_core library when needed

update.py

#!/usr/bin/env python

import os.path as p
import subprocess
import sys

DIR_OF_THIS_SCRIPT = p.dirname( p.abspath( __file__ ) )
DIR_OF_YCMD = p.join( DIR_OF_THIS_SCRIPT, 'third_party', 'ycmd' )

sys.path.insert( 1, DIR_OF_YCMD )
sys.path.insert( 1, p.join( DIR_OF_YCMD, 'ycmd' ) )

import server_utils


def Main():
  if not server_utils.CompatibleWithCurrentCore():
    print( 'The ycm_core library is up to date.' )
    sys.exit()
  build_file = p.join( DIR_OF_THIS_SCRIPT, 'install.py' )
  python_binary = sys.executable
  subprocess.check_call( [ python_binary, build_file ] + sys.argv[1:] )

if __name__ == "__main__":
  Main()