Changes in version: equateIRT_1.1

* Added functions import.ltm, import.flexmirt and import.irtpro 
  to import item parameters estimates and covariance matrices 
  from the R package ltm, and external programs flexmirt and irtpro.
* In function modIRT:
	- the default value of arguments ltparam and lparam is TRUE.
	- argument var can be set to NULL, that is the default value.
	- argument names can be set to NULL, that is the default value.
	- added arguments display and digits.
* In functions direc and alldirec:
	- removed argument itmp.
* In function convert:
	- implemented conversion of person parameters.
* Added dataset data2pl.
* Some changes in Rd files.


