Missing setup tags are added.

Previously, os_settings tag overrided setup tags.  Now both tags are specified to coexist.
README.md is revised for better instructions.
task names are changed to be more descriptive by including phase names.

These are only cosmetic changes.
The retry process is re-written using "until:" and "retries:"

This is a refactoring effort to change the playbook simplar.
Permission checks for glimpse DB files are added.

Strangely in some cases, the permission of glimpse DB files become 0400 instead of 0644.  This change mitigates the issue.
The default name for lxr_tag_name is changed a bit.
Patching lxr.conf to add ".git" now does not affect the following cp task.

A bugfix. Two reasons: 1. ansible seems buggy if "when:" is used with "or" and "|".  2. patching should be done only when lxr.conf needs an update, and the result of patching is not important.
A playbook to reboot the target machines is added.

When disabling SELinux, the target machine needs a reboot.  This playbook helps to do the reboot.