Fix buffer overflow, Add MDT detail sub-window

[ofaaland]

Three commits:

• Fix an overflow while copying a string containing recovery status. The recovery status is copied from the lmt_mdt message into a local string, while looping over the MDTs. The code contained an incorrect calculation of the maximum allowable length, so the strncpy or equivalent call could overflow the destination buffer.
• Fix a compile warning about an uninitialized variable, by initializing it during declaration.
• Create a separate sub-window listing each MDT, in addition to the existing one listing each OST. Allow for sorting, collapsing MDTs to MDSs, like the existing OST window.