Move adb to C++.

I keep trying to clean things up and needing std::strings. Might as
well just do this now.

usb_linux_client.c is going to stay as C because GCC isn't smart
enough to deal with the designated initializers it uses (though for
some reason it is in C mode).

The Darwin files are staying as C because I don't have a way to test
that they build.

The Windows files are staying as C because while I can actually build
for them, it's slow and painful.

Change-Id: I75367d29205a9049d34460032b3bb36384f43941
diff --git a/adb/adb_io.cpp b/adb/adb_io.cpp
index ca208ad..4dd9f4d 100644
--- a/adb/adb_io.cpp
+++ b/adb/adb_io.cpp
@@ -33,7 +33,7 @@
 
     D("readx: fd=%d wanted=%zu\n", fd, len);
     while (len > 0) {
-        int r = TEMP_FAILURE_RETRY(adb_read(fd, p, len));
+        int r = adb_read(fd, p, len);
         if (r > 0) {
             len -= r;
             p += r;
@@ -69,7 +69,7 @@
 #endif
 
     while (len > 0) {
-        r = TEMP_FAILURE_RETRY(adb_write(fd, p, len));
+        r = adb_write(fd, p, len);
         if (r == -1) {
             D("writex: fd=%d error %d: %s\n", fd, errno, strerror(errno));
             if (errno == EAGAIN) {