add 'raco dependencies-graph'

That is, refactor DrRacket's module browser so that
it can be run outside of DrRacket.

pkgs/drracket-pkgs/drracket/drracket/info.rkt

@@ -89,3 +89,8 @@
     'white-on-black-base? #t
     'colors tol-white-on-black-colors)))
 
+(define raco-commands
+  (list (list "dependencies-graph"
+              'drracket/private/standalone-module-browser
+              "opens a GUI window showing transitive module dependencies (aka `Module Browser')"
+              #f)))

pkgs/drracket-pkgs/drracket/drracket/private/main.rkt

@@ -179,9 +179,6 @@
                            3/4
                            number-between-zero-and-one?))
 
-(drr:set-default 'drracket:module-browser:name-length 1 
-                         (λ (x) (memq x '(0 1 2 3))))
-
 (let ([frame-width 600]
       [frame-height 650]
       [window-trimming-upper-bound-width 20]
@@ -271,15 +268,6 @@
  null
  list?)
 
-  (drr:set-default 'drracket:module-overview:label-font-size 12 number?)
-  (drr:set-default 'drracket:module-overview:window-height 500 number?)
-  (drr:set-default 'drracket:module-overview:window-width 500 number?)
-  (drr:set-default 'drracket:module-browser:hide-paths '(lib)
-                           (λ (x)
-                             (and (list? x)
-                                  (andmap symbol? x))))
-  
-
 (drracket:font:setup-preferences)
 (color-prefs:add-color-scheme-preferences-panel
  #:extras

pkgs/drracket-pkgs/drracket/drracket/private/standalone-module-browser.rkt

@@ -0,0 +1,10 @@
+#lang racket/base
+(require racket/cmdline racket/runtime-path)
+
+(define file (command-line #:args (file) file))
+
+(define-runtime-path module-browser.rkt "module-browser.rkt")
+(define standalone-module-overview/file 
+  (dynamic-require module-browser.rkt 'standalone-module-overview/file))
+
+(standalone-module-overview/file file)

pkgs/drracket-pkgs/drracket/drracket/private/unit.rkt

@@ -5342,4 +5342,3 @@
         (check-true (string? 
                      (compute-label-string 
                       (string->path (make-string i #\x)))))))))
-

pkgs/string-constants-pkgs/string-constants-lib/string-constants/private/english-string-constants.rkt

@@ -1394,7 +1394,7 @@ please adhere to these guidelines:
  (module-browser-filename-format "Full Filename: ~a (~a lines)")
  (module-browser-root-filename "Root Filename: ~a")
  (module-browser-font-size-gauge-label "Font Size")
- (module-browser-progress-label "Module overview progress")
+ (module-browser-progress-label "Module Browser Progress")
  (module-browser-adding-file "Adding file: ~a...")
  (module-browser-laying-out-graph-label "Laying out graph")
  (module-browser-open-file-format "Open ~a")