Implemented the option for procedure-name truncation

[timakin]

Overview

Added an option to truncate too long method name. This pull-request is designed for https://github.com/giginet/xcprofiler/issues/9

Usage

$ xcprofiler biwako-ios -t 30
...
| AppDelegate.swift           | 34   | final get {}                   | 0.02     |
| AppDelegate.swift           | 24   | @objc deinit                   | 0.01     |
| AppDelegate.swift           | 96   | @objc func applicationWillR... | 0.01     |
| AppDelegate.swift           | 116  | @objc func applicationWillT... | 0.01     |
| AppDelegate.swift           | 142  | @objc func gotoSetting()       | 0.01     |
...

Notice

• The default limit is 150

[giginet]

Could you update README?