Allow changing template whitespace

By default templates use tabs. Unfortunately there are misguided
heretics who prefer spaces. Bummer.

Two variables are introduced:

* SP=<number> can be set to use <number> spaces per indentation level.
* WS=<string> can be set to use <string> for each indentation level.

Most users will just want to use SP, for example:

  make new t=gen_server n=my_server SP=4

Note that people who want tabs don't have to do anything; tabs
are still the default.

WS is reserved for advanced users. Normal Make rules apply: all
whitespaces are trimmed. To specify 4 spaces using WS, you can
do the following:

  make new t=gen_server n=my_server WS='$(empty)    $(empty)'

Ugly, right? So just use SP.

Finally, SP and WS can be put in your Makefile directly.
In fact, erlang.mk will automatically add SP to a newly
created project if it was used during creation. For example:

  make -f erlang.mk bootstrap SP=2

So in time we should only need to make a note in the docs
at project creation time, as there is very little value
after that point.

1 files changed, 1 insertions, 0 deletions

diff --git a/core/core.mk b/core/core.mk
index ad70ee6..2bf717a 100644
--- a/core/core.mk
+++ b/core/core.mk
@@ -119,6 +119,7 @@ help::
 
 empty :=
 space := $(empty) $(empty)
+tab := $(empty)	$(empty)
 comma := ,
 
 define newline