Merge pull request #91 from jooooooon/bug_3803/rudder_agent_init_script_ignores_the_opt_rudder_etc_disable_agent_flag_file

Fixes #3803: rudder-agent init script ignores the /opt/rudder/etc/disabl...
Fixes #3802 - Adapt function 'check_and_add_config_property' to add properties into file in argument and permit to add Apache configuration of Rudder 2.7
Refs #3802 - Use better check for apache parameters
Refs #3802 - Fix typos
Refs #3802 - prevent from exiting the file at the begining if no Apache configuration is found and use single quote in order to prevent some evil interpretations
Refs #3802 -Fix typo in check of New API access rule and reformat output
Merge pull request #92 from nperron/bug_3802/int/ensure_apache_conf_fro_2.7_is_added_during_migration

Bug 3802/int/ensure apache conf fro 2.7 is added during migration
Fixes #3805: rudder-agent init script doesn't always returns 0 on status operation