Moved $_error load statement lower.

This prevents a possible recursion when an error is trigerred by one of the config file.
Also since the variable is used only later in the code it makes sense to move it lower.
Merge pull request #2891 from cristik/develop

Moved $_error load statement lower.
Fixed typos in Migration library documentation

Signed-off-by: Jacob Tabak <Jacob.Tabak@HelloWorld.com>
Merge pull request #2892 from jacobtabak/develop

Fixed typos in Migration library documentation
Add compatibility layer for array_column(), array_replace(), array_replace_recursive()
Don't use error suppression with ini_set()
Date helper days_in_month(), CI_Calendar::get_total_days() changes

 - days_in_month() now uses cal_days_in_month(), if available.
 - CI_Calendar::get_total_days() is now an alias for days_in_month().
[ci skip] Fix date helper loading in CI_Calendar::get_total_days()
Fix CI_Calendar tests
Remove a few empty 'mock' classes
CI_Utf8-related changes

 - Give priority to mb_convert_encoding() over iconv() in clean_string() (partially fixes #261)
 - Add more proper unit tests
Don't use error suppression on ini_get() either
Try to fix Travis not excluding pgsql,mysqli for HHVM
Method CI_URI::_fetch_uri_string() has been removed, removal of reference.
Merge pull request #2896 from ivantcholakov/develop

Method CI_URI::_fetch_uri_string() has been removed.
[ci skip] Update a changelog entry
CI_Upload changes

- Method chaining support.
- A more abstract resetting of the default settings.
- Added an option to initialize() to disable resetting to default settings.
- Removed method mimes_types() and slightly optimized chunks of code where it was used.
- Added the ability to pass allowed_types as an array.
Add test cases for CI_Upload::__construct(), CI_Upload::initialize()
Remove CI_Calendar::

Only use it in generate().
Minor improvements to CI_FTP