bos: Don't overflow cellname buffer

Don't overflow the fixed sized cellname buffer when copying the
information in from the command line - instead, just use a
dynamically allocated buffer.

Caught by coverity (#985775)

Change-Id: If87b1ba9bcb990d3145a89627e212144cd78f5a0
Reviewed-on: http://gerrit.openafs.org/9549
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
bos: Don't overflow buffer with key data

When parsing key data from the command line, don't overflow the
buffer used to hold it - instead just give an error if the data
is too long.

Caught by coverity (#985775)

Change-Id: I44fb62d30c5022e650475b3ca51a28bcb7cf1e06
Reviewed-on: http://gerrit.openafs.org/9550
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
bos: Remove theoretical overflow in DateOf

DateOf copies the results of ctime into a static buffer. Typically
ctime will return a 26 byte string, but if you pass it a year larger
than 9999 (which we shouldn't), you can get a 32 (or more) byte string.

Get rid of this unlikely event by using strlcpy for the copy. We already
truncate at 24 bytes when we remove the \n, so this shouldn't cause any
further problems.

Really, this whole thing should be rewritten to use strftime.

Caught by coverity (#985776)

Change-Id: I18f6828d6ec3d79ecaf1dad8e27d3e8691ce87d5
Reviewed-on: http://gerrit.openafs.org/9551
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>