Add blobtool

Add command line tool "blobtool" for examining the binary store:
listing and reading blobs. The modification are not supported.

The tool is enabled in the build by default and can be disabled
by running configure script with "--disable-blobtool" option.

Signed-off-by: Maksym Sloyko <maxims@google.com>
Change-Id: Ibed6df639e541fd5100dbbc032846cbc15340654
diff --git a/configure.ac b/configure.ac
index 5ea68ed..cc0fc6d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,6 +36,17 @@
     AS_HELP_STRING([--enable-oe-sdk], [Link testcases absolutely against OE SDK so they can be ran within it.])
 )
 
+# Add --disable-blobtool flag to configure script
+AC_ARG_ENABLE([blobtool],
+    AS_HELP_STRING([--disable-blobtool], [Disable blobtool, command line tool to inspect the blobs]),
+    [case "${enableval}" in
+        no) build_blobtool=false;;
+        *) build_blobtool=true;;
+    esac],
+    [build_blobtool=true]
+)
+AM_CONDITIONAL([BUILD_BLOBTOOL], [ test x${build_blobtool} = xtrue ])
+
 # Check for OECORE_TARGET_SYSROOT in the environment.
 AC_ARG_VAR(OECORE_TARGET_SYSROOT,
     [Path to the OE SDK SYSROOT])