Fix #2406 query builder cache

Signed-off-by: GDmac <grdalenoort@gmail.com>
docs: get_compile_select

get_compile_select(null,false) without reset also preserves LIMIT settings
Merge branch 'develop' of https://github.com/EllisLab/CodeIgniter into develop
Cleanup PR #2719

for Fix #2406 query builder cache

Signed-off-by: GDmac <grdalenoort@gmail.com>
Merge pull request #2719 from GDmac/develop

Fix #2406 query builder cache