build: fix webtalk clean target

cant have multiple identically named targets - newer overrides older.
Merge pull request #398 from mhaberler/master

build: fix webtalk clean target
scara config - doesn't run atm, but eventually the code should support such a config
changed message names from _AXIS_ to _JOINT_
Ferror is now a joint property.
first pass at fixing joints/axes issues. doesn't quite compile yet..
add a couple of hacks (and further fixes) to make it compile/run. grep for FIXME-AJ for remaining issues
started changing jogging NML commands (EMC_JOG_CONT, EMC_JOG_INCR, EMC_JOG_ABS and EMC_JOG_STOP)

The original version of this commit added to halui.cc a function called
sendJogIncr(), with an "r".  But after the rebase of joints_axes3 to
joints_axes4, the parent version of halui.cc in the new starting place
in master already has a function called sendJogInc(), without the "r".

joints_axes4 changed this commit to follow the naming convention in
master.
fix function names for jogging
changed jogging NML commands (EMC_JOG_CONT, EMC_JOG_INCR, EMC_JOG_ABS and EMC_JOG_STOP)
update AXIS for changed jogging NML commands (EMC_JOG_CONT, EMC_JOG_INCR, EMC_JOG_ABS and EMC_JOG_STOP)
remove *teleop_vector*, those will be handled by regular jog messages (with motion controller in TELEOP mode, not in joint mode)
remove comment, it has been fixed
remove an older reference for num_joints (unused ..)
add default values for AXIS vel & acc limits
fix having values for AXIS vel & acc limits
reenable EMC_AXIS_MAX
- reenable iniAxis* used for reading additional things from AXIS_X, Y, .. sections
in the ini.

these are things like:
* carthesian HOME position
* MIN/MAX limits (for box shaped workspace limiting)
* MAX_VEL/ACC for carthesian speed/accel limiting

- replace EMC_JOINT_LINEAR and ANGULAR with EMC_LINEAR and EMC_ANGULAR
(they are used for joints, but also for axes in some places)
* add taskintf functions for setting Axis related things (min/max position, max vel/acc..)
* change EMC_JOINT_LINEAR to EMC_LINEAR (same for ANGULAR): sometimes used for AXES too
add a comment about some wrongly done limit checks