Delete assign() to .GlobalEnv, and use dput() and dum()

To avoid the note of R CMD check
Ignore this: just use formatR to change the format

Almost nothing changed here.
Ignore this: just use formatR to change the format

There is no big change here.
Updation the iBUGS.rd
Ignore this: no change
Change the title of the package
Change the figures of the interface
Update the contents and tone of the vignette