I guess fixed uminus in quantity.Function is still buggy.

quantity.Discrete & quantity.Symbolic: plus and minus now support quantity and numeric arrays of same size.

- plot() added option to hide array indices in title >> 'titleWithIndex', false
- l2norm() calculate quadratic norm

quantity.Symbolic: bugfix in subs() and use of quantity.Symbolic constructor for the result of int()

quantity.Discrete.gridOf() if quantity has no grid that coincides with the input gridName, then an [] is returned.

- solveAlgebraic: adjusted to change of changeGrid from call-by-reference to call-by-value
- diff(): now supports specification of various variables for which the derivative should be applied. Ensured consistency with Symbolic. Maybe a more elegant use of gradient() is possible.
- unittests: adjusted for now behavior of diff()

quantity.Symbolic bugfixes:
- diff(): now supports specification of various variables for which the derivative should be applied. Ensured consistency with Discrete.
- unittests: adjusted for now behavior of diff()

misc.subsurf: allow myTitle as cell, in order to support x_ij(z,t) with ij added between first and second myTitle cell-element (myTitle = {'x', '(z,t)'})

Changed implementation of integration for "Discretes". The input arguments are now consitent with the matlab "int" function.

misc.Gain(s): Classes to enease implementation of input or feedback gains when the number and kind of input is arbitrary (for instance, if you want to add a disturbance input later)

*) Allow to set empty quantity.Discrete objects with certain size
*) added the isConstant property for the quantity.Discrete
*) Implemented a cast to the quantity.Operator object
*) Implemented a cast of empty quantity.Discretes to quantity.Symbolics
*) Fixed bug in "on()" for constant quantities
*) Fixed some functions to work with empty quantities
*) Added a settings object to use global settings
*) plot function returns now an array of the figure handles
*) Re-implementation of the quantity.Operator object

quantity.Symbolic: Bugfixes in subs and abs, inv, exp, expm... this constructor is really messy for constant values

- minor bugfixes in: obj2value, vec2diag, cumInt
- comments in: plus, int, greek2tex