OpenMx 0.2.4-1038 released

This release contains several bug fixes and new features. Here is the list of changes from the previous release.

• definition variables can now be used inside algebra expressions
• definition variables inside of MxMatrices will populate to the 1st row before conformability checking. In plain english: you do not need to specify the starting values for definition variables.
• the square-bracket operator when used in MxMatrix labels is no longer restricted to constants for the row and column. The row and column arguments will accept any term that evaluates to a scalar value or a (1 x 1) matrix.
• summary() on a model returns a S3 object. Behaves like summary() in stats package.
• eliminated UnusualLabels.R test case. Too many problems with windows versus OS X versus linux.
• implemented vech() and vechs() functions: half-vectorization and strict half-vectorization
• fixed bug in ordinal FIML when # of data columns > # of thresholds
• added 'frontendTime' and 'backendTime' values to summary() output. They store the elapsed time of a model in the R front-end and C back-end, respectively.
• created a name space for the OpenMx library. Only mx**() and omx**() functions should be exported to the user, plus several miscellaneous matrix functions and S4 generic functions.
• corrected 'observedStatistics' output of summary() to exclude definition variables
• corrected 'observedStatistics' output of summary() count the number of equality constraints