upgrade to latest LSP

[akosyakov]

vscode compatiblity layer is introduced to make use of vscode-languageclient directly instead of vscode-base-languageclient

[akosyakov]

Please review.

• I've finished the implementation of VS Code compatibility layer with LSP and Monaco: https://github.com/TypeFox/monaco-languageclient/pull/89/files#diff-9b485517654cf1807a16cc585e670df4. This layer only implements APIs which are used by vscode-languageclient. Resolution of VS Code module should be adjusted by clients, for example with webpack: https://github.com/TypeFox/monaco-languageclient/pull/89/files#diff-9bb3de20ef60fb0751fb0025b2cd27ea
• API-wise there are some minor breaking changes: https://github.com/TypeFox/monaco-languageclient/pull/89/files#diff-412ff84fa2527e608a8217ca35f1a30c Major change is the switch to ES6. vscode-languageclient is targeting it, so we either have to switch to ES6 or fork it again and compile down to ES5. I would like to go for ES6, since it supported by all latest browsers: https://kangax.github.io/compat-table/es6/. Clients can still transpile it to ES5 via webpack with babel-loader.
• I've also added support of latest LSP features:

  monaco-languageclient/src/services.ts

  Lines 173 to 176 in 1a8247c

  	registerImplementationProvider?(selector: DocumentSelector, provider: ImplementationProvider): Disposable;
  	registerTypeDefinitionProvider?(selector: DocumentSelector, provider: TypeDefinitionProvider): Disposable;
  	registerColorProvider?(selector: DocumentSelector, provider: DocumentColorProvider): Disposable;
  	registerFoldingRangeProvider?(selector: DocumentSelector, provider: FoldingRangeProvider): Disposable;

  They are implemented via Monaco as well, except folding. For folding first we have to upgade to latest Monaco. I will do it as a separate PR.

As the next step i am going to publish next version and test it with Theia.

[rcjsuen]

I didn't scrutinize the changes super thoroughly as there's quite a bit but I gave it a test run with my own language server and it seemed okay. Great work, Anton!

[akosyakov]

@rcjsuen many thanks for trying it out

[AlexTugarev]

LGTM!

[akosyakov]

We've decided to keep vscode-base-languageclient as a vscode-languageclient transpiled to es5. As soon as microsoft/vscode-languageserver-node#382 is resolved, we can abandon vscode-base-languageclient completely.