In the interest of performance and simplicity. lsp-ui-doc is redundant
with +lookup/documentation and eldoc (which are less imposing than
lsp-ui-doc's childframe).
Also sets lsp-groovy-server-install-dir.
Still needs to be documented, but includes support for the following
languages:
+ C/C++/ObjC
+ Go
+ Java
+ Javascript
+ OCaml
+ PHP
+ Python
+ Ruby
+ Scala
+ Swift
+ HTML/CSS
Relevant to #460, #716, #1186