Automatic versioning for aptly

New version format:

* for releases, `x.y.z` (follows tag without leading `v`)
* for nightly builds, `x.y.z+N+hash` (previous version, not the upcoming one)

This means that each nightly build `aptly` would report
correct version now.

Version is now complied into the aptly binary, system tests
automatically check for current version, no need to update them
anymore.

Makefile

@@ -1,6 +1,6 @@
 GOVERSION=$(shell go version | awk '{print $$3;}')
+VERSION=$(shell git describe --tags | sed 's@^v@@' | sed 's@-@+@g')
 PACKAGES=context database deb files http query swift s3 utils
-ALL_PACKAGES=api aptly context cmd console database deb files http query swift s3 utils
 PYTHON?=python
 TESTS?=
 BINPATH?=$(GOPATH)/bin
@@ -39,12 +39,12 @@ check:
 	gometalinter --vendor --vendored-linters --config=linter.json ./...
 
 install:
-	go install -v
+	go install -x -v -ldflags "-X main.Version=$(VERSION)"
 
 system-test: install
 	if [ ! -e ~/aptly-fixture-db ]; then git clone https://github.com/aptly-dev/aptly-fixture-db.git ~/aptly-fixture-db/; fi
 	if [ ! -e ~/aptly-fixture-pool ]; then git clone https://github.com/aptly-dev/aptly-fixture-pool.git ~/aptly-fixture-pool/; fi
-	PATH=$(BINPATH)/:$(PATH) $(PYTHON) system/run.py --long $(TESTS)
+	APTLY_VERSION=$(VERSION) PATH=$(BINPATH)/:$(PATH) $(PYTHON) system/run.py --long $(TESTS)
 
 travis: $(TRAVIS_TARGET) check system-test
 
@@ -79,4 +79,7 @@ goxc:
 man:
 	make -C man
 
-.PHONY: coverage.out man
+version:
+	@echo $(VERSION)
+
+.PHONY: coverage.out man version