Made the build system accept --cfgfile and --modfile

Also added a dir of example configs.
This contributes to #1.

build-production.cfg

@@ -0,0 +1,5 @@
+optimise yes
+listmods no
+test yes
+log yes
+opath kernel.lua

build.lua

@@ -19,10 +19,19 @@ end
 print("Initializing and reading configuration")
 ts={}
 tA = {...}
+for k,v in ipairs(tA) do
+ if type(v) == "string" then
+  if v:sub(1,10) == "--cfgfile=" then
+   cfgfile = v:sub(11)
+  elseif v:sub(1,10) == "--modfile=" then
+   modfile = v:sub(11)
+  end
+ end
+end
 ss=""
+cfgfile = cfgfile or "build.cfg"
+modfile = modfile or "modules.cfg"
 cfg={}
-cfgfile = tA[1] or "build.cfg"
-modfile = tA[2] or "modules.cfg"
 f=io.open(cfgfile,"rb")
 repeat
  line = f:read("*l")

configs/desktop.cfg

@@ -0,0 +1,14 @@
+base/header.lua
+drivers/dterm.lua
+library/print.lua
+drivers/keyboard.lua
+library/net.lua
+library/fs-min.lua
+library/fs-std.lua
+library/fs-ext.lua
+util/fs-automount.lua
+applications/shutil.lua
+applications/evproxy-srv.lua
+applications/evproxy-client.lua
+applications/luash.lua
+base/footer.lua

configs/minimal-net-rexec.cfg

@@ -0,0 +1,4 @@
+base/header.lua
+library/net.lua
+applications/rexec.lua
+base/footer.lua

configs/minimal-net.cfg

@@ -0,0 +1,3 @@
+base/header.lua
+library/net.lua
+base/footer.lua

configs/minimal.cfg

@@ -0,0 +1,2 @@
+base/header.lua
+base/footer.lua

modules.cfg

@@ -8,5 +8,7 @@ library/fs-std.lua
 library/fs-ext.lua
 util/fs-automount.lua
 applications/shutil.lua
+applications/evproxy-srv.lua
+applications/evproxy-client.lua
 applications/luash.lua
 base/footer.lua