Defer ListVersions() on already-fetched git repos

This was causing potentially unnecessary network activity, as well as
placing a block that effectively serialized slow points in the solving
algorithm.

Author: sdboyer

maybe_source.go

@@ -82,10 +82,11 @@ func (m maybeGitSource) try(cachedir string, an ProjectAnalyzer) (source, string
 	}
 
 	src.baseVCSSource.lvfunc = src.listVersions
-
-	_, err = src.listVersions()
-	if err != nil {
-		return nil, "", err
+	if !r.CheckLocal() {
+		_, err = src.listVersions()
+		if err != nil {
+			return nil, "", err
+		}
 	}
 
 	return src, ustr, nil
@@ -129,10 +130,11 @@ func (m maybeGopkginSource) try(cachedir string, an ProjectAnalyzer) (source, st
 	}
 
 	src.baseVCSSource.lvfunc = src.listVersions
-
-	_, err = src.listVersions()
-	if err != nil {
-		return nil, "", err
+	if !r.CheckLocal() {
+		_, err = src.listVersions()
+		if err != nil {
+			return nil, "", err
+		}
 	}
 
 	return src, ustr, nil

source_manager.go

@@ -305,7 +305,6 @@ func (sm *SourceMgr) DeduceProjectRoot(ip string) (ProjectRoot, error) {
 }
 
 func (sm *SourceMgr) getSourceFor(id ProjectIdentifier) (source, error) {
-	//pretty.Println(id.ProjectRoot)
 	nn := id.netName()
 
 	sm.srcmut.RLock()