New version for RBaseX

Hi, I am glad that version 0.2.4 from my R-package 'RBaseX' has been accepted by CRAN (https://cran.r-project.org/package=RBaseX)! Large parts of the earlier version from the R-package 'RBaseX' have been rewritten and the resulting code is much cleaner. I have added tests and thanks to those test, I found (and fixed) several bugs. To my knowledge, the full server-protocol has now been implemented. One of the main differences concerns error-handling. All client-requests to the basexserver end with either a \00 byte or a \01. I have used this feature to add an extra layer of error-handling. The default is still the regular tryCatch method. But after setting 'intercept' to TRUE, you can now define your reaction upon errors. See the following example: Session <- BasexClient$new("localhost", 1984L, username = "admin", password = "admin")

Session$set_intercept(TRUE)
Session$Execute("drop DB TestDB")
Session$Execute("Open TestDB")
if (!Session$get_success()) {
  Session$Create("TestDB")
  Session$Add("Test.xml", "<Line_1 line='1'>Content 1</Line_1>")
}
Session$Execute("Close")
Session$restore_intercept()

I am already working on a new version in which I will implement more specific R-related topics (populating dataframes with XQuery-results. Ben