The map file is a temporary file, ignore it.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>
Support go install at Makefile and resolve OS depended map file creation.

The binary has different names on different operating systems.
Until the 'go build' command has no support for map files the
only way to generate the system table is the 'nm' tool. NM requires
the correct binary file name.

The 'go install' command is not powerful enough for my deployment
step. We've three steps to go:

  * build and install binary at $(GOPATH)/bin
  * generate map file at $(GOPATH)/bin
  * copy static a2l to $(GOPATH)/bin

The first two steps could be merged with the -ldflags '-map' option.
I'll propagate it to the gophers.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>