(Qcurrent_input_method, Qactivate_input_method): New
variables.
(syms_of_minibuf): Intern and staticpro them.
(read_minibuf): New argument INHERIT_INPUT_METHOD. If it is
nonzero, remember the current input method in INPUT_METHOD, and
activate it after switching to the minibuffer.
(Fread_from_minibuffer): New argument INHERIT_INPUT_METHOD.
(Fread_minibuffer): Call read_minibuf with INHERIT_INPUT_METHOD
nil.
(Fread_string): New argument INHERIT_INPUT_METHOD.
(Fread_no_blanks_input): Likewise.
(Fread_command): Call Fcompleting_read with INHERIT_INPUT_METHOD
nil.
(Fread_function, Fread_variable, Fread_buffer): Likewise
(Fcompleting_read): New argument INHERIT_INPUT_METHOD.