Improve handling of program list (for snabb --help)

Several small fixes:

- Add src/program/programs.inc to gitignore
- Fix 'FORCE' rule trick in Makefile to ensure it is updated
- Fix usage printout to program names with punctiation (e.g. example_foo)

.gitignore

@@ -14,3 +14,4 @@ obj
 /src/syscall.lua
 /src/syscall
 /deps/*.vsn
+/src/program/programs.inc

src/Makefile

@@ -190,10 +190,10 @@ $(INCOBJ): obj/%_inc.o: %.inc Makefile program/programs.inc | $(OBJDIR)
 	$(Q) luajit -bg -n $(subst /,.,$*)_inc $(basename $@).luainc $@
 
 # Create list of programs that exist
-program/programs.inc:
+program/programs.inc: FORCE
 	@ls -1d program/*/ | xargs basename -a > $@
 
-.FORCE: program/programs.inc
+FORCE:
 
 # extra/ third party bits and pieces
 obj/strict.o: extra/strict.lua | $(OBJDIR)

src/core/main.lua

@@ -59,7 +59,7 @@ end
 
 function usage ()
    print("Usage: "..ffi.string(C.argv[0]).." <program> ...")
-   local programs = require("program.programs_inc"):gsub("[a-z]+", "  %1")
+   local programs = require("program.programs_inc"):gsub("%S+", "  %1")
    print()
    print("This snabb executable has the following programs built in:")
    print(programs)