* mi-cmds.c (-environment-directory) Change to use mi_cmd_env_dir,
(-environment-cd): Change to use mi_cmd_env_cd,.
(-environment-pwd): Change to use mi_cmd_env_pwd.
(-environment-path): Change to use mi_cmd_env_path.
* mi-cmds.h (mi_cmd_env_cd, mi_cmd_env_dir): New prototypes.
(mi_cmd_env_path, mi_cmd_env_pwd): Ditto.
* mi-cmd-env.c: New file. Part of fix for PR gdb/741.
* gdbmi.texinfo (environment-cd): Update output and example.
(environment-pwd): Ditto.
(environment-dir): Update output, description, and examples.
(environment-path): Ditto.
* mi-cmds.h: Export mi_cmd_data_write_register_values.
* mi-cmds.c (mi_cmds): Implement data-write-register-values with
mi_cmd_data_write_register_values.
* mi-main.c (mi_cmd_data_write_register_values): New
function. Write a value into a register.
