minor build improvements (#1281)

* fix maiden-repl dependency checking

* edge.sh: fail fast, limit build parallelism

assuming the target audience for `edge.sh` is a less technical
person testing unreleased features it makes sense to exit as
soon as one of the commands fails (such as `waf configure`) instead
of continuing on to produce a bad build or errors which obscure
the initial problem.

limiting parallelism is a safety. building more than two of the
c++ components in parallel with the matron/crone/supercollider running
will somewhat often run out of memory and fail. limiting the build
to two jobs leaves ~100Mb of headroom during a clean build

edge.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
+set -e
 cd "$(dirname "$0")"
 git pull
 git submodule update
 ./waf configure
-./waf
-
+./waf -j2

maiden-repl/wscript

@@ -7,8 +7,7 @@ def options(opt):
 def configure(conf):
     conf.load('compiler_c compiler_cxx')
 
-    conf.check_cfg(package='pthread', args=['--cflags', '--libs'])
-    conf.check_cfg(package='readline', args=['--cflags', '--libs'])
+    # libraries with full pkg-config data
     conf.check_cfg(package='ncursesw', args=['--cflags', '--libs'])
     conf.check_cfg(package='panel', args=['--cflags', '--libs'])
     conf.check_cfg(package='nanomsg', args=['--cflags', '--libs'])
@@ -31,8 +30,6 @@ def build(bld):
                 ],
 
                 use=[
-                    'PTHREAD',
-                    'READLINE',
                     'NCURSESW',
                     'PANEL',
                     'NANOMSG'

wscript

@@ -17,6 +17,8 @@ def options(opt):
     opt.add_option('--enable-ableton-link', action='store_true', default=True)
     opt.add_option('--profile-matron', action='store_true', default=False)
 
+    opt.recurse('maiden-repl')
+
 def configure(conf):
     conf.load('compiler_c compiler_cxx boost')
 
@@ -72,6 +74,8 @@ def configure(conf):
     conf.env.ENABLE_ABLETON_LINK = conf.options.enable_ableton_link
     conf.define('HAVE_ABLETON_LINK', conf.options.enable_ableton_link)
 
+    conf.recurse('maiden-repl')
+
 def build(bld):
     bld.recurse('matron')
     bld.recurse('maiden-repl')