Moves C++ global build properties to properties file to match Java.

Adds host reachability check and static IP fallback
Adds roboRIO Image check
Adds JRE check for Java

Change-Id: I07f3a0863bde0ebec7e7d8f48270e45758bddba5

eclipse-plugins/edu.wpi.first.wpilib.plugins.java/src/main/resources/java-zip/ant/build.properties

@@ -9,6 +9,7 @@ debug.flag.dir=/tmp/
 debug.flag.command=chown lvuser:ni ${debug.flag.dir}frcdebug
 command.dir=/home/lvuser/
 version=current
+roboRIOJRE.dir=/usr/local/frc/JRE
 
 # Libraries to use
 wpilib=${user.home}/wpilib/java/${version}
@@ -21,6 +22,7 @@ networktables.sources=${wpilib.lib}/NetworkTables-sources.jar
 #jnaerator.jar=${wpilib.lib}/jnaerator-runtime.jar
 #classpath=${wpilib.jar}:${networktables.jar}:${jna.jar}:${jnaerator.jar}
 classpath=${wpilib.jar}:${networktables.jar}
+roboRIOAllowedImages=18
 
 # Ant support
 wpilib.ant.dir=${wpilib}/ant