add *.swp to .gitignore
fix a typo: md_send_metadat_update to md_send_metadata_update
change dlm_md_idle to dlm_md_token to keep align with the documentation
rewrite message transmitting protocol

raid1_sendd: a thread for sending message
raid1_recvd: a thread for receiving message
replace struct msg_suspend,msg_metadata_update,msg_resync_finish with struct cluster_msg for message passing
fix typos

1, sequence number in doc/message-update.txt
2, mddev->avail_bitmap[1] in raid1.c
add bmpno parameter for bitmap number in api: md_send_suspend()
add message handler for suspend and sync finish

handle_suspend_range(): add the range in the mddev->suspend_range list
When a write bio in one of the range list, will put this bio into
conf->retry_list.When a read bio in the range list, will select the
right device to read(haven't implemented yet)
hanle_sync_finished: remove the relative range and maybe flag.and wake
up mddev->thread to write the suspended bio
Merge pull request #2 from ldzhong/master

rewrite message transmitting protocol and message handler for suspend and sync finish