feat(mako): mako autosetup and improved executable

Now we can write mako templates, with a similar feature set as
pyratemp. Except that its syntax is nicer, allows to do everything
and that there is syntax highlight support.

Let's see how it fares

Makefile

@@ -2,11 +2,14 @@
 
 include Makefile.helpers
 
-PYTHON = python2.7
-TPL = etc/bin/pyratemp.py
+VENV := virtualenv
+VENV_DIR := .pyenv
+PYTHON := $(VENV_DIR)/bin/python
+PIP := $(VENV_DIR)/bin/pip
+MAKO_RENDER := ./etc/bin/mako-render
+TPL := $(PYTHON) $(MAKO_RENDER)
 
-API_DEPS_TPL = src/pyra/deps.pyra
-API_MAIN_TPL = src/pyra/main.pyra
+API_DEPS_TPL = src/mako/deps.mako
 API_DEPS = .api.deps
 API_SHARED_INFO = ./etc/api/shared.yaml
 API_JSON_FILES = $(shell find ./etc -type f -name '*-api.json')
@@ -20,14 +23,21 @@ help:
 	$(info api-deps     -   generate a file to tell make what API file dependencies will be)
 	$(info help-api     -   show all api targets to build individually)
 
-$(API_DEPS): $(API_SHARED_INFO) $(API_DEPS_TPL)
-	$(TPL) -f $(API_SHARED_INFO) $(API_DEPS_TPL) > $@
+$(PYTHON):
+	virtualenv $(VENV_DIR)
+	$(PIP) install mako pyyaml
+
+$(MAKO_RENDER): $(PYTHON)
+
+$(API_DEPS): $(API_SHARED_INFO) $(API_DEPS_TPL) $(MAKO_RENDER)
+	$(TPL) --data-files $(API_SHARED_INFO) $(API_DEPS_TPL) > $@
 
 api-deps: $(API_DEPS)
 
 include $(API_DEPS)
 
-clean: clean-api
+clean:
+	-rm -Rf $(VENV_DIR)
 	-rm $(API_DEPS)