Summary:
When arcanist connects to a phorge site which uses an SSL certificate signed by a local CA, then the client needs to have a resources/ssl/custom.pem file as per resources/ssl/README
As this is client specific it should be in the .gitignore file.
Also update resources/ssl/README to replace [Pp]habricator with [Pp]horge.
Test Plan:
```
touch resources/ssl/custom.pem
git status
```
The 'git status' should show no changes.
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Differential Revision: https://we.phorge.it/D25304
Summary: Ref T13395. Moves all remaining code in "libphutil/" into "arcanist/".
Test Plan: Ran various arc workflows, although this probably has some remaining rough edges.
Maniphest Tasks: T13395
Differential Revision: https://secure.phabricator.com/D20980
