Fixed various CMS_MODULE.install, by not marked module installed if an error occurred!

Improved Auth related module implementation by having a way to change settings like token, max age.
  - use CMS_SETUP.site_id and related "auth.$module.token" ... configuration values.
  - removed related CMS_..._CONSTANTS classes.

For auth session module, use auth_session as table name, and use VARCHAR(64).
Extracted sql from blog module, and store it under site/scripts/install.sql .
Renamed a few $modulename.sql as install.sql

examples/demo/site/modules/blog/scripts/install.sql

@@ -0,0 +1,6 @@
+CREATE TABLE blog_post_nodes(
+  `nid` INTEGER NOT NULL CHECK("nid">=0),
+  `revision` INTEGER NOT NULL,
+  `tags` VARCHAR(255),
+  CONSTRAINT PK_nid_revision PRIMARY KEY (nid,revision)
+);