Add a configuration define to specify the name of the application's main() entry point.
  This was previously hardcoded as aim_main().
  It is now specified as the value of the AIM_CONFIG_AIM_MAIN_NAME configuration define.
  The default value of AIM_CONFIG_AIM_MAIN_NAME is aim_main().
  This change has no effect on existing code.
Merge into master from pull request #19:
Allow customization of the aim_main() function name. (https://github.com/floodlight/infra/pull/19)