Add a listener for IOException

如果在读取串口数据的过程中，设备断线了，线程会抛出IOException。此时应当关闭串口输入，再尝试重新打开

Allow user to set read delay

Merge pull request #1 from evision-ai/feat/set-read-delay-when-initia…

…lizing-serial-port-manager

allow user to set read delay when initializing serial port manager

Fix an input stream null pointer issue

2.0.6

fix a null pointer crash issue