Add Timer class

This class is used to call a callback function
when the timer expires.  It can be one shot, or repeating.

Copied from the phosphor-fan-presence repository.

Change-Id: I9d63c2e6fd550286a2a5360e1e8d13f6a3c25923
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1f4edce
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,26 @@
+*.o
+*.lo
+*.la
+*.sw*
+Makefile
+Makefile.in
+configure
+.deps
+.libs
+aclocal.m4
+ar-lib
+arm-openbmc-linux-gnueabi-libtool
+autom4te.cache/
+compile
+config.guess
+config.h
+config.h.in
+config.log
+config.status
+config.sub
+depcomp
+install-sh
+i586-openbmc-linux-libtool
+ltmain.sh
+missing
+stamp-h1