Add shears script

Taken from msysgit.msysgit rev 9fda80

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>
Mark shears.sh as an executable

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
shears: Enhance the documentation substantially

This was suggested by Thomas Braun.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
shears: add an example

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
shears: branch names can also contain underscores

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix DOS line endings

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #1 from dscho/add_shears

shears: Enhance the documentation substantially
Merge pull request #18 from t-b/add_shears

Add shears script