bug#24829: 24.5; `easy-mmode-define-navigation': rename `define-...', per convention

[Drew Adams]

Macro `easy-mmode-define-navigation' apparently defines Emacs commands
(functions).  Per the Emacs Lisp coding conventions, its seems that the
macro should be renamed.

>From (elisp `Coding Conventions':

  Constructs that define a function or variable should be macros, not
  functions, and their names should start with `define-'.  The macro
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  should receive the name to be defined as the first argument.  That
  will help various tools find the definition automatically.  Avoid
  constructing the names in the macro itself, since that would
  confuse these tools.


In GNU Emacs 24.5.1 (i686-pc-mingw32)
 of 2015-04-11 on LEG570
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=3D/c/usr --host=3Di686-pc-mingw32'