Improving assumptions about offset parameter in StrposOptimizer.

Signed-off-by: Rack Lin <racklin@gmail.com>
add $context->headersManager->add('kernel/operators');

Signed-off-by: Rack Lin <racklin@gmail.com>
Improving trim/ltrim/rtrim supports charlist parameter .

Signed-off-by: Rack Lin <racklin@gmail.com>
Added some exists check optimizers.

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #82 from racklin/bugfix/subpos

Improving assumptions about offset parameter in StrposOptimizer.
Merge pull request #83 from racklin/enhancement/trim_support_2param

Improving trim/ltrim/rtrim supports charlist parameter .
Merge pull request #84 from racklin/enhancement/exists

Added some exists check optimizers.
Merge branch 'original/master'