Bump libtool version (not package version) to 1:0:1.

Bump libtool version (not package version) to 1:0:1.

The last release (0.1.0) had the libtool version (current:revision:age)
set to 0:0:0. Since this release doesn't change/remove any
interfaces (it does *add* new interfaces, though), 'current' and 'age'
are increased and 'revision' is set to 0, resulting in 1:0:1.

http://www.gnu.org/software/libtool/manual/libtool.html#Updating-version-info

Programs using libserialport don't need to be recompiled or relinked.