Support snippet compilation

Original handling of snippets only worked if the current selected theme was a staticTheme. This now fully merges all snippets through the theme chain no matter what the top-level theme is. So user themes built on 5ePHB can benefit from 5ePHB snippets too.

User input of user snippets will be a later PR, but merging them into static snippets is now supported.

client/homebrew/pages/editPage/editPage.jsx

@@ -424,6 +424,7 @@ const EditPage = createClass({
 						reportError={this.errorReported}
 						renderer={this.state.brew.renderer}
 						userThemes={this.props.userThemes}
+						snippetBundle={this.state.themeBundle.snippets}
 					/>
 					<BrewRenderer
 						text={this.state.brew.text}