docs(views): Updated docs for elgg_extend_view() to address uniqueness of extended views.

Fixes #6661
Merge pull request #6663 from brettp/views_docs

docs(views): Updated docs for elgg_extend_view() to address uniqueness of extended views.
feature(core): allow custom local scripts to trigger on uncaught exceptions #6586
Merge pull request #6606 from beck24/custom-exceptions

feature(core): allow custom local scripts to trigger on uncaught exceptions
chore(merge): resolve 1.8/master conflicts
Merge pull request #6750 from ewinslow/merge-1.8

Merge 1.8 to master