a big patch; use special proxy types (Input/OutputArray, Input/OutputArrayOfArrays) for passing in vectors, matrices etc.

added IPP dot product functions. Only 32f data type supported for now (there are accuracy issues in 8u/16s/16u/32s functions which will be fixed in IPP 7.0.3)

replaced alloca() (a.k.a. cvStackAlloc) with AutoBuffer or vector() everywhere. cvStackAlloc() is still defined, but we do not need alloca() anymore to compile and run OpenCV (fixes #889 and may be some others)

added hconcat & vconcat functions for joining matrices; moved some inline functions out of the headers; fixed several bugs in documentation; removed MatND from docs