* mh-identity.el (mh-assoc-ignore-case): New macro that uses
assoc-string (if the function is available) and falls back on
assoc-ignore-case if assoc-string is not found.
(mh-identity-field-handler): Use mh-assoc-ignore-case since
assoc-ignore-case is a obsolete function in Emacs 22.
* mh-e.el (mh-folder-buttons-init-flag): New variable that keeps
track of whether the tool-bar in mh-folder-mode has been
initialized yet.
(mh-folder-mode): Initialize the tool-bar for folders the first
time we get into mh-letter-mode.
* mh-customize.el (mh-buffer-exists-p): New function which tests
presence of buffers of a given mode.
(mh-tool-bar-define): New functions
mh-tool-bar-folder-buttons-init and
mh-tool-bar-letter-buttons-init are defined. These functions are
used to create the tool-bar from the corresponding customizable
variables.
* mh-comp.el (mh-letter-buttons-init-flag): New variable that
keeps track of whether the tool-bar in mh-letter-mode has been
initialized yet.
(mh-letter-mode): Initialize the tool-bar for drafts the first
time we get into mh-letter-mode.