Update profiling.rst

There is some confusion about how to enable profiling for queries. This will save some time for devs who want to debug their generated SQL.
Update profiling.rst

correcting rst syntax
Merge pull request #3059 from manuganji/patch-1

Update profiling.rst
Fix #3057
fix callable hooks
fix callable hooks
Merge pull request #3065 from dtmax/develop

fix calling of callable hooks
A fix about loading language files - ensuring suffix '_lang' presence properly.
Merge pull request #3072 from ivantcholakov/develop

A fix about loading language files - ensuring suffix '_lang' presence properly.
Added _display documentation.
[ci skip] Update changelog
[ci skip] Update changelog
Remove CI_Encrypt::_xor_encode()
Add support for non-ASCII domain names in FV & Email classes' valid_email()

Depends on the Intl extension
Fixed code style.
reduced line length.
Fix wrong variable name
Merge pull request #3074 from aanbar/output_documentation

Added _display documentation.
Fix a potential undefined variable error
Merge branch 'develop' of github.com:EllisLab/CodeIgniter into develop