API refactoring

[tzaeschke]

Some API changes:

• Rename DatagramChannel to ScionDatagramChannel
• Rename DatagramSocket to ScionDatagramSopcketl and move it to main package
• Rename ScionSocketOptions starting with SN_ to SCION_

[codecov]

Codecov Report

Attention: Patch coverage is 62.23565% with 125 lines in your changes are missing coverage. Please review.

Files	Coverage Δ	Complexity Δ
src/main/java/org/scion/jpan/DatagramChannel.java	0.00% <ø> (-96.43%)	0.00 <0.00> (-13.00)
...c/main/java/org/scion/jpan/ScionSocketOptions.java	72.72% <100.00%> (ø)	1.00 <1.00> (ø)
src/main/java/org/scion/jpan/ScmpChannel.java	85.84% <ø> (ø)	16.00 <0.00> (ø)
.../scion/jpan/internal/SelectingDatagramChannel.java	82.50% <ø> (ø)	8.00 <0.00> (?)
src/main/java/org/scion/jpan/ScionService.java	70.99% <50.00%> (ø)	49.00 <1.00> (ø)
...n/java/org/scion/jpan/AbstractDatagramChannel.java	86.93% <66.66%> (ø)	77.00 <0.00> (ø)
...main/java/org/scion/jpan/ScionDatagramChannel.java	96.42% <96.42%> (ø)	13.00 <13.00> (?)
...ain/java/org/scion/jpan/socket/DatagramSocket.java	0.00% <0.00%> (-54.79%)	0.00 <0.00> (-57.00)
.../main/java/org/scion/jpan/ScionDatagramSocket.java	54.78% <54.78%> (ø)	57.00 <57.00> (?)