Update to the 2019 wpilib

Lots of gratuitious incompatibilities to deal with. Started sanifying a
few classes rather than figuring out how to update them too. Has not yet
been tested on a robot, but everything still builds so it should be
fine.

Also ported over our FPGA timestamp fixes, which were previously only in
allwpilib_2018.

Also upgraded to the new roborio compiler, which has to happen at the
same time due to incompatible pre-compiled libraries.

Change-Id: Ib9b6ad8fc0112d90a9855afe1b706588ef4ebde9
diff --git a/tools/build_rules/select.bzl b/tools/build_rules/select.bzl
index 2d0bce5..8754f26 100644
--- a/tools/build_rules/select.bzl
+++ b/tools/build_rules/select.bzl
@@ -40,9 +40,9 @@
     if key not in all_cpus and key != 'else':
       fail('Not sure what a %s CPU is!' % key, 'values')
   return select({
-    '//tools:cpu_k8': values['amd64'],
-    '//tools:cpu_roborio': values['roborio'],
-    '//tools:cpu_armhf': values['armhf'],
+    '@//tools:cpu_k8': values['amd64'],
+    '@//tools:cpu_roborio': values['roborio'],
+    '@//tools:cpu_armhf': values['armhf'],
   })
 
 """A select wrapper for address space sizes.
@@ -58,9 +58,9 @@
   if '64' not in values:
     fail('Need to handle 64 bit addresses!', 'values')
   return select({
-    '//tools:cpu_k8': values['64'],
-    '//tools:cpu_roborio': values['32'],
-    '//tools:cpu_armhf': values['32'],
+    '@//tools:cpu_k8': values['64'],
+    '@//tools:cpu_roborio': values['32'],
+    '@//tools:cpu_armhf': values['32'],
   })
 
 """A select wrapper for compilers.