Move templates outside the source .mk filestemplates

Templates now no longer use Make variables for substitution
but instead replace strings with their equivalent:

  template_name: Corresponds to n=template_name
  project_name:  Corresponds to $(PROJECT) or in=project_name

This allows defining templates outside of Makefiles. For
example an external plugin could define their templates
in templates/my_template.erl and then have the following
in the included Makefile:

  tpl_my_template = $(file < $(THIS)/templates/my_template.erl)

By default the created file will be in src/template_name.erl.
This can be overriden with the tplp_* variable:

  tplp_my_template = src/model/my_template.erl

Substitution is applied both to the template contents and
to its path.

In addition, attempting to overwrite an existing file when
creating a template will result in failure.

1 files changed, 42 insertions, 0 deletions

diff --git a/templates/gen_server.erl b/templates/gen_server.erl
new file mode 100644
index 0000000..d297edf
--- /dev/null
+++ b/templates/gen_server.erl
@@ -0,0 +1,42 @@
+-module(template_name).
+-behaviour(gen_server).
+
+%% API.
+-export([start_link/0]).
+
+%% gen_server.
+-export([init/1]).
+-export([handle_call/3]).
+-export([handle_cast/2]).
+-export([handle_info/2]).
+-export([terminate/2]).
+-export([code_change/3]).
+
+-record(state, {
+}).
+
+%% API.
+
+-spec start_link() -> {ok, pid()}.
+start_link() ->
+	gen_server:start_link(?MODULE, [], []).
+
+%% gen_server.
+
+init([]) ->
+	{ok, #state{}}.
+
+handle_call(_Request, _From, State) ->
+	{reply, ignored, State}.
+
+handle_cast(_Msg, State) ->
+	{noreply, State}.
+
+handle_info(_Info, State) ->
+	{noreply, State}.
+
+terminate(_Reason, _State) ->
+	ok.
+
+code_change(_OldVsn, State, _Extra) ->
+	{ok, State}.