Adding SRGen to build scripts (#45)

* Adding SRGen to build scripts

Adding support for sr.strings files. sr.strings files can be converted
into .resx and designer cs files by running the SRGen Cake target
Adding a new target to Cake script to run SRGen. SRGen is pulled down as a
nuget package for Cake and executes from the .tools folder.
Adding Cake temp environment to the gitignore
Adding the cake scripts to the sqltoolsservice solution file

* Fixes from pull request comments

* Fix as per @llali

* Actual changes as per @llali

* removing platform type from netcore dependency

src/Microsoft.SqlTools.ServiceLayer/project.json

@@ -24,7 +24,12 @@
   },
   "frameworks": {
     "netcoreapp1.0": {
-      "imports":  "dnxcore50"
+      "dependencies": {
+        "Microsoft.NETCore.App": {
+          "version": "1.0.0"
+        }
+      },
+      "imports": "dnxcore50"
     }
   },
   "runtimes": {