Captcha and design works.

Added captcha generation. As we're working without JS - there is no
possibility to reload image, only if user will reload whole web page.

Some design works - set monospace font for paste textarea (will
use system-defined default monospace font) and lowered font size
in paste views.

cmd/fastpastebin/fastpastebin.go

@@ -32,6 +32,7 @@ import (
 
 	// local
 	"github.com/pztrn/fastpastebin/api"
+	"github.com/pztrn/fastpastebin/captcha"
 	"github.com/pztrn/fastpastebin/context"
 	"github.com/pztrn/fastpastebin/database"
 	"github.com/pztrn/fastpastebin/database/migrations"
@@ -59,6 +60,7 @@ func main() {
 	api.New(c)
 	api.InitializeAPI()
 
+	captcha.New(c)
 	pastes.New(c)
 
 	// CTRL+C handler.