Minor compile cleanup
  - Add .gitignore
  - Changed ASFVOLT_LOG macro to recognize printf paramter warnings
  - Removed -Wno-sign-compare from make.  Fix warning in the source.

Change-Id: I5d98b327d906e980509ce071b5060c95635746a1
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2065572
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,23 @@
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo