Allow HOMEBREW_EDITOR for non-project editing.

If set, use "HOMEBREW_EDITOR" when editing a single file, or multiple
files in the same folder.

Note that this setting does not affect `brew edit`, since opening
all of Homebrew at once requires an editor with proper project support.

Library/Contributions/manpages/brew.1.md

@@ -149,6 +149,14 @@ didn't include with OS X.
   * HOMEBREW\_DEBUG:
     If set, instructs Homebrew to always assume `--debug` when running commands.
 
+  * HOMEBREW\_EDITOR:
+    If set, Homebrew will use this editor when editing a single formula, or
+    several formulae in the same folder.
+
+    *NOTE*: `brew edit` will open all of Homebrew as discontinuous files and
+    folders. TextMate can handle this correctly in project mode, but many
+    editors will do strange things in this case.
+
   * HOMEBREW\_SVN:
     When exporting from Subversion, Homebrew will use `HOMEBREW_SVN` if set,
     a Homebrew-built Subversion if installed, or the system-provided binary.
@@ -165,7 +173,8 @@ didn't include with OS X.
     configurations.)
 
   * HOMEBREW\_USE\_LLVM:
-    If set, instructs Homebrew to use the LLVM front-ends to the GCC compilers.  
+    If set, instructs Homebrew to use the LLVM front-ends to the GCC compilers.
+
     *NOTE*: Not all formulae will build correctly under LLVM.
 
   * HOMEBREW\_VERBOSE:

Library/Homebrew/utils.rb

@@ -140,11 +140,16 @@ def puts_columns items, cols = 4
 end
 
 def exec_editor *args
-  editor=ENV['EDITOR']
+  editor = ENV['HOMEBREW_EDITOR'] || ENV['EDITOR']
   if editor.nil?
     if system "/usr/bin/which -s mate"
+      # TextMate
       editor='mate'
+    elsif system "/usr/bin/which -s edit"
+      # BBEdit / TextWrangler
+      editor='edit'
     else
+      # Default to vim
       editor='/usr/bin/vim'
     end
   end

share/man/man1/brew.1

@@ -164,6 +164,13 @@ HOMEBREW_DEBUG
 If set, instructs Homebrew to always assume \fB\-\-debug\fR when running commands\.
 .
 .TP
+HOMEBREW_EDITOR
+If set, Homebrew will use this editor when editing a single formula, or several formulae in the same folder\.
+.
+.IP
+\fINOTE\fR: \fBbrew edit\fR will open all of Homebrew as discontinuous files and folders\. TextMate can handle this correctly in project mode, but many editors will do strange things in this case\.
+.
+.TP
 HOMEBREW_SVN
 When exporting from Subversion, Homebrew will use \fBHOMEBREW_SVN\fR if set, a Homebrew\-built Subversion if installed, or the system\-provided binary\.
 .
@@ -181,7 +188,7 @@ This issue typically occurs when using FileVault (or certain custom SSD configur
 HOMEBREW_USE_LLVM
 If set, instructs Homebrew to use the LLVM front\-ends to the GCC compilers\.
 .
-.br
+.IP
 \fINOTE\fR: Not all formulae will build correctly under LLVM\.
 .
 .TP