GitLab

* Added GLYCAM

* Improved tests and documentation

* Fixed incorrect external bonds

* Adding support for new AMOEBA features

* Support modern method of specifying in-plane angles

* Implemented stretch-torsions

* Implemented angle-torsions

* More AMOEBA fixes

* Bug fix

* Converted AMOEBA 2018 force field

* Added documentation for AMOEBA 2018

* Added a missing file for tests

* Created OBC2 that works with current force fields

* Created HCT, OBC1, GBn, and GBn2 that works with current force fields

* Added documentation for GB models

* Updates to documentation and tests based on comments

* Added formula for screening parameter

* Break user guide into parts

* Break up file I missed

* Add basic .gitignore to suit out-of-tree builds in build, build1, build2 ... build9

* Small changes to autonumber.py for doc compilation

This is a small change designed not to fix the incorrect logic of
autonumber.py, but just to get the docs compiling. While assigning
numbers, the code now just ignores the autonumber_by_chapter
setting for a particular object if it can't find the appropriate
section in section_numbers. This is a temporary fix!

* Include part and chapter in autonumbered objects

* Fix autonumber.py to correctly reference autonumber roles in file-level sections

* Unify and simplify styling across documentation

* Break dev docs down into individual chapter-files

* Correct absolute links to relative

* Disable browser suggestions for lunrsearch box in API docs

* Remove part name from chapter 2.1

* Rename ambiguous 'Home' link to OpenMM.org

* Typo

* Minor fixes...