Refactor ErrorNavItem to not need "this" parameter

Toward making edit/new/home pages functional, which do not have "this"

client/homebrew/pages/editPage/editPage.jsx

@@ -438,6 +438,13 @@ const EditPage = createClass({
 		return `https://www.reddit.com/r/UnearthedArcana/submit?title=${encodeURIComponent(title.toWellFormed())}&text=${encodeURIComponent(text)}`;
 	},
 
+	clearError : function(){
+		setState({
+			error    : null,
+			isSaving : false
+		})
+	},
+
 	renderNavbar : function(){
 		const shareLink = this.processShareId();
 
@@ -449,7 +456,7 @@ const EditPage = createClass({
 			<Nav.section>
 				{this.renderGoogleDriveIcon()}
 				{this.state.error ?
-					<ErrorNavItem error={this.state.error} parent={this}></ErrorNavItem> :
+					<ErrorNavItem error={this.state.error} clearError={clearError}></ErrorNavItem> :
 					<Nav.dropdown className='save-menu'>
 						{this.renderSaveButton()}
 						{this.renderAutoSaveButton()}