Fixed coordinate frame transformations for grasping (which now works again)
Moved grasp- and pregrasp-offset poses into global variables
Removed obsolete code
Moved grasping into separate file, added sensors

The grasping-related code is now found in the `grasping.lisp' file rather than the `handled-objects.lisp' file. The reason is that the grasping code was refactored to spread over objects with as well as without handles.
Also, added fingertip sensors handling code. The function `(pressure-fingertip side finger)' now gives a pseudo-filtered value of the current requested sensor. The function `(zero-fingertip-pressure side)' must called before using the sensors. When opening a gripper, the respective side's zero point is set automatically.
Fixed zero-ing of the fingertip sensor data
Changed the number of samples for fingertip filtering to 8 and changed filter

The filter used for getting the current value of fingertip sensors is changed to exponential weights
Fixed a mistake while calculating the exponentially weighted average for fingers
Added convenience-functions for palm-side and top-side finger part pressures
Corrected a comment on new filter
Added pull and push actions and revised grasping reasoning code
Fixed grasping related reasoning and unified grasping for objects with and without handles
Fixed grasping offsets and the function for deciding grasp distances
Fixed a tf timing issue, added convenience fnc for relative linear motion
Added symbols for push and pull actions
Fixed parking arms when no objects are held
Now *actually* fixed the arm parking when no object is in hand
Further refined the pregrasp offset
Added check for whether grasping an object actually worked or not
Refactored put-down code to work with non-constrained IKs and check tf before transforming
Changed a published topic name and removed debug info