add absolutePaths option to CFileHelper::findFiles

if absolutePaths is true (by default), function will return absolute paths, otherwise the relative ones
mbstring fallback for CFileHelper::findFiles
code conv fix, charset specifying and docs improvement
Merge remote-tracking branch 'upstream/master' into patch-1
CHANGELOG updated
Merge remote-tracking branch 'upstream/master'
another way to return relative paths: findFilesRecursive main loop instead of findFiles post-processing
CClientScriptTest has been advanced to expose issue #2770
CClientScript::renderScriptBatch() has been fixed to group scripts with different HTML options correctly.
Issue #2770 has been added to CHANGELOG
CClientScript::renderScriptBatch() has been improved to sort html options only if they are specified.
Merge branch 'master' of github.com:yiisoft/yii into 2770-client-script-render-script-batch
use proper table name with schema when creating a multi insert command
detect properly if criteria->select starts with a count() expression in CActiveFinder->count() method
updated CHANGELOG
Update Database Schema Component

Update the CDbSchema component to allow passing columns names to CDbSchema::createIndex() and CDbSchema::addForeignKey() as an array, as well as a string of comma-separated column names.
Update Framework Unit Tests

Update the frameworks unit tests to check incoming data types for the column names of CDbSchema::createIndex() and CDbSchema::addForeignKey().
Add Issue #2817 to CHANGELOG
Update Method Parameters in CDbSchema::createIndex()

Update the spelling of the third parameter of CDbSchema::createIndex() to become plural, rather than singular, to better reflect the correct data that this parameter accepts.
Merge pull request #2818 from mynameiszanders/2817-cdbschema-inconsistent-accepted-data-types-in-method-parameters

Issue #2817 - CDbSchema: Inconsistent Accepted Data Types in Method Parameters