Better support for using field names and rule parameters in error messages.
Merge branch 'refs/heads/develop' into feature/form_error_msgs
Merge branch 'develop' of https://github.com/EllisLab/CodeIgniter into feature/form_error_msgs
Merge branch 'develop' of https://github.com/EllisLab/CodeIgniter into feature/form_error_msgs

Conflicts:
	system/language/english/form_validation_lang.php
Fix a merge oopsie in the language file.
Combine this feature with Fix Issue #935 in another pull request.
Fix modify_column() issues (#2020)
Manually apply a fix submitted via PR #2012, #2016
[ci skip] Fix a typo in the styleguide
Added support for stream-like downloads of existing files to force_download()

Based on code/ideas from PR #365, #1254
Fix issue #118 (manually implementing PR #1832)
3.0.0-dev: Fixing the issue #2023.

CI_Cart initialization: Session data presense should be tested against NULL, not FALSE.
Merge pull request #2024 from ivantcholakov/develop

3.0.0-dev: Fixing the issue #2023.
Fix #113
[ci skip] Remove a lone semicolon (rel 2d48b4f1a174473fa0539769a433ba78305c0faa)
Minor changes to Xmlrpc.php
Minor changes to Xmlrpcs.php
Merge pull request #2025 from vkeranov/develop

Some minor changes to Xmlrpc.php and Xmlrpcs.php
keep_flashdata accepts array
Bug fix - optimize_table() in DB utility class