Allow explicitly and unconditionally setting the generator to use

(Address issue #33)

package.json

@@ -169,6 +169,11 @@
                         "NMake Makefiles"
                     ],
                     "description": "The preferred CMake generator(s) to use when configuring (tried in order of listing)"
+                },
+                "cmake.generator": {
+                    "type": "string",
+                    "default": null,
+                    "description": "The CMake generator to use"
                 },
                 "cmake.parallelJobs": {
                     "type": "number",

src/cmake.ts

@@ -1016,6 +1016,12 @@ export class CMakeTools {
 
     // Given a list of CMake generators, returns the first one available on this system
     public async pickGenerator(candidates: string[]): Promise<Maybe<string>> {
+        // The user can override our automatic selection logic in their config
+        const generator = this.config<Maybe<string>>('generator');
+        if (generator) {
+            // User has explicitly requested a certain generator. Use that one.
+            return generator;
+        }
         for (const gen of candidates) {
             if (!gen)
                 continue;