replace SVN version and date information by GIT information

NEW: I overlooked in the first commit the file: blind/plot-constellations.c and fixed it in the second commit


Hello Dustin,

I created in boilerplate.h two macros 
BOILERPLATE_HELP_HEADER, BOILERPLATE_ADD_FITS_HEADERS
and replaced the old function calls by
the macros. In the Makefile I fetched the GIT information as described in our previous discussion
and created a version.h file:

PRG_GIT_REVISION := $(shell git describe)
PRG_GIT_DATE := $(shell git log -n 1 --format=\"%cd\")
PRG_GIT_URL := "https://github.com/dstndstn/astrometry.net"

define VERSION_H
/* Generated file, do not edit. */
#define PRG_GIT_REVISION "$(PRG_GIT_REVISION)"
#define PRG_GIT_DATE $(PRG_GIT_DATE)
#define PRG_GIT_URL $(PRG_GIT_URL)
endef
export VERSION_H

version:
        @echo "$$VERSION_H" > version.h
.PHONY: version

RELEASE_VER := $(shell echo $(PRG_GIT_REVISION) | cut -f1 -d"-")

RELEASE_DIR := astrometry.net-$(RELEASE_VER)

Cheers
 Thomas