Changelog: Use changelogplease for git parsing

Fixes gh-7
Closes gh-53

Author: scottgonzalez

lib/changelog.js

@@ -1,16 +1,20 @@
-var fs = require( "fs" );
+var fs = require( "fs" ),
+	changelogplease = require( "changelogplease" );
 
 module.exports = function( Release ) {
 
 Release.define({
-	_generateChangelog: function() {
-		var changelogPath = Release.dir.base + "/changelog",
-			changelog = Release.changelogShell() +
-				Release._generateCommitChangelog() +
-				Release._generateIssueChangelog();
-
-		fs.writeFileSync( changelogPath, changelog );
-		console.log( "Stored changelog in " + changelogPath.cyan + "." );
+	_generateChangelog: function( callback ) {
+		Release._generateCommitChangelog(function( commitChangelog ) {
+			var changelogPath = Release.dir.base + "/changelog",
+				changelog = Release.changelogShell() +
+					commitChangelog +
+					Release._generateIssueChangelog();
+
+			fs.writeFileSync( changelogPath, changelog );
+			console.log( "Stored changelog in " + changelogPath.cyan + "." );
+			callback();
+		});
 	},
 
 	changelogShell: function() {
@@ -21,39 +25,21 @@ Release.define({
 		return Release.newVersion;
 	},
 
-	_generateCommitChangelog: function() {
-		var commits,
-			commitRef = "[%h](" + Release._repositoryUrl() + "/commit/%H)",
-			fullFormat = "* %s (TICKETREF, " + commitRef + ")",
-			ticketUrl = Release._ticketUrl();
-
+	_generateCommitChangelog: function( callback ) {
 		console.log( "Adding commits..." );
-		Release.chdir( Release.dir.repo );
-		commits = Release.gitLog( fullFormat );
-
-		console.log( "Adding links to tickets..." );
-		return commits
-
-			// Add ticket references
-			.map(function( commit ) {
-				var tickets = [];
-
-				commit.replace( /Fix(?:e[sd])? #(\d+)/g, function( match, ticket ) {
-					tickets.push( ticket );
-				});
-
-				return tickets.length ?
-					commit.replace( "TICKETREF", tickets.map(function( ticket ) {
-						return "[#" + ticket + "](" + ticketUrl + ticket + ")";
-					}).join( ", " ) ) :
-
-					// Leave TICKETREF token in place so it's easy to find commits without tickets
-					commit;
-			})
 
-			// Sort commits so that they're grouped by component
-			.sort()
-			.join( "\n" ) + "\n";
+		changelogplease({
+			ticketUrl: Release._ticketUrl() + "{id}",
+			commitUrl: Release._repositoryUrl() + "/commit/{id}",
+			repo: Release.dir.repo,
+			committish: Release.prevVersion + ".." + Release.newVersion
+		}, function( error, log ) {
+			if ( error ) {
+				Release.abort( "Error generating commit changelog.", error );
+			}
+
+			callback( log );
+		});
 	},
 
 	_generateIssueChangelog: function() {