Fix some man page errors.

Resolves: rhbz#948850

Signed-off-by: Peter Jones <pjones@redhat.com>
Get rid of pe_allocspace(), it isn't useful.

It only has one caller, and the only information that caller provides is "8".

Signed-off-by: Peter Jones <pjones@redhat.com>
Make pe_shorten_file() exported.

Signed-off-by: Peter Jones <pjones@redhat.com>
Eliminate incorrect msync() usage when writing out signed files.

Before:

mremap(0x7f4080ccf000, 5541080, 5538272, 0) = 0x7f4080ccf000
ftruncate(7, 5538272)                   = 0
ftruncate(7, 5543488)                   = 0
mremap(0x7f4080ccf000, 5538272, 5543488, MREMAP_MAYMOVE) = 0x7f4080ccf000
msync(0x7f40812171e0, 5216, MS_SYNC)    = -1 EINVAL (Invalid argument)
munmap(0x7f4080ccf000, 5543488)         = 0
close(7)                                = 0

After:

mremap(0x7f79a23f0000, 5541080, 5538272, 0) = 0x7f79a23f0000
ftruncate(7, 5538272)                   = 0
ftruncate(7, 5543488)                   = 0
mremap(0x7f79a23f0000, 5538272, 5543488, MREMAP_MAYMOVE) = 0x7f79a23f0000
ftruncate(7, 5545984)                   = 0
mremap(0x7f79a23f0000, 5543488, 5545984, MREMAP_MAYMOVE) = 0x7f79a23f0000
msync(0x7f79a23f0000, 5545984, MS_SYNC) = 0
mremap(0x7f79a23f0000, 5545984, 5543488, 0) = 0x7f79a23f0000
ftruncate(7, 5543488)                   = 0
munmap(0x7f79a23f0000, 5543488)         = 0
close(7)                                = 0

Which is larger and not quite so pretty, but it also isn't erroneous.

Signed-off-by: Peter Jones <pjones@redhat.com>
Fix a comment for future work to not be misleading.

Signed-off-by: Peter Jones <pjones@redhat.com>