Added exceptions for open() and close() methods (issue #8)
Added exceptions for open() and close() methods (issue #8)
Merge remote-tracking branch 'origin/master'

Conflicts:
	pi4j-core/src/main/java/com/pi4j/io/serial/Serial.java
	pi4j-core/src/main/java/com/pi4j/io/serial/SerialException.java
	pi4j-core/src/main/java/com/pi4j/io/serial/impl/SerialImpl.java
Changed return type of com.pi4j.io.serial.Serial::open() from int to void (with Exceptions, returning anything doesn't make sense)
Merge pull request #36 from jderda/master

Fixed issue #8; added serial exceptions