Reversed the rotary encoder return values (left = down, right = up)

As stated in the debug output, turning the encoder left should
result in a Down button press, while turning right should be
interpreted as Up button.
Fixes #2: glcd.so has missing dependencies

Add missing objects and libraries to glcd_LDADD and glcd_DEPENDENCIES.
Fix trailing whitespaces.
Update autoconf/automake configuration and remove manually edited Makefile.

This allows LCDproc to be compiled as usual, using configure, make, make install.
The USBBAT driver is build when --enable-libusb is selected together with
the glcd driver.
Update README.md

Reordered steps: copy files should happen before configuring LCDproc, so the newest acinclude.m4 and Makefile.am are used.
This way, configure picks up the usbbat driver.
Merge pull request #4 from thdankert/master

Fix issue #2 and #3 (missing dependencies and rotary encoder reversed)