Refactor libfastboot

This change creates a nice and clean API for issuing
fastboot commands without using the fastboot tool itself.

Test: fastboot tool itself (now using libfastboot2)
on sailfish, walleye, and other devices.
Test: flash bootloader bootloader.img
Test: flash radio radio.img
Test: -w update img.zip
Test: Manually getvar and reboot commands.

Bug: 111126621
Change-Id: I0022536b204ce0c5ad8329367fd522fa3c57877d
diff --git a/fastboot/main.cpp b/fastboot/main.cpp
index f1c8afb..c3683f7 100644
--- a/fastboot/main.cpp
+++ b/fastboot/main.cpp
@@ -26,9 +26,9 @@
  * SUCH DAMAGE.
  */
 
-#include "fastboot.h"
+#include "engine.h"
 
 int main(int argc, char* argv[]) {
-    FastBoot fb;
+    FastBootTool fb;
     return fb.Main(argc, argv);
 }