* Add user-defined category-label colors
Fixes https://github.com/chanzuckerberg/cellxgene/issues/1152
As described in https://github.com/chanzuckerberg/cellxgene/issues/1307
* Respond to feedback from @bkmartinjr in nodejs
* Respond to feedback from @bkmartinjr in python
* Add tests to the server module
* Autoformat python, run linter
* Make colors_get error handling specific
* Respond to feedback from @bkmartinjr
* Respond to feedback from @bkmartinjr
* Fix whitespace
* Fix python lint errrors
* Update documentation
* Add --disable-user-colors option to launch and cxgtool.py
* Fix python formatting
* Rename '--disable-user-colors' to '--disable-custom-colors'
* fix improper branch link
* set app to use dataset link
* temp repo change
* revert to master
* add options var
* tweak option order
* remove options config arg
* initial cut at backed mode
* make flask multithreading conditional on debug flag
* update X access to support backed mode
* lint
* improve help message for backed mode
* fix tests
* add MatrixProxy to normalize supported matrix types
* add FAQ entry for --backed
* remove use of matrix.T
* clean up
* add ability to disable diffexp from CLI; add hueristic to detect likely slow diffexp calculation, and warn user
* fix tests
* do not print diffexp speed warning if diffexp is disabled
* tweak wording of diffexp speed messages
* add FAQ entry on --disable-diffexp
* revise heuristic for warning about slow diffexp
* use quick tooltip delay on diffexp button
* initial commit of URL support for launch
* lint
* modify tests to use new data locator
* add locator unit tests
* fix typo in faq
* more lint
* update faq per PR review
* Update example datasets w/ pbmc3k and tabula muris
* Add `prepare` overview and example
* Add S3 data links
* Incorporate PR feedback & copyedits
* Switch to letter pointers
* unix line endings
* path
