Update link to Cloudera Manager web page.

Thanks to Harsh for pointing it out.
[docs] Doc updates

- Fix typos
- Change uses of CM to "Cloudera Manager"
- Add spark and accumulo to supported services
[CLOUDERA-BUILD] making changes to push 5.2.0 api
 Adding missing 5.2.0 page internally
Add v9 API doc (CM 5.3.0)
Add v9 javadoc (CM 5.3.0)
Add v9 epydoc (CM 5.3.0)
 Bumping up version to 5.3.0
Update 5.3.0 cm_api