[R-package] miscellaneous changes to comply with CRAN requirements (#3338)

* [R-package] update DESCRIPTION per CRAN comments

* newlines

* Apply suggestions from code review
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* more fixes

* update Rbuildignore

* more changes

* more changes per CRAN response

* add email

* run examples in CI

* add newest CRAN response

* add Solaris patch

* update patch

* another attempt at ifaddrs patch

* fix unnecessary comment

* update configure

* comments

* bump version

* tabs

* fix address alignment, required by cran (#3415)

* fix dataset binary file alignment

* many fixes

* fix warnings

* fix bug

* Update file_io.cpp

* Update file_io.cpp

* simplify code

* Apply suggestions from code review

* general

* remove unneeded alignment

* Update file_io.h

* int32 to byte8 alignment

* Apply suggestions from code review

* Apply suggestions from code review

* [R-package] add new copyright holder in DESCRIPTION (#3409)

* [R-package] add new copyright holder in DESCRIPTION

* fix role

* fixing conflicts

* [R-package] add new copyright holder in DESCRIPTION (#3409)

* [R-package] add new copyright holder in DESCRIPTION

* fix role

* trying to fix conflicts

* more fixes

* this will work

* update cran-comments

* simplify solaris, add more testing docs

* stuff

* remove rchck docs

* Apply suggestions from code review
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* remove extra use of cat()

* change solaris check

* update docs

* remove testing code

* fix warning about cleanup not having execute permissions

* fix cmake builds

* remove blank line
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>
Co-authored-by: Guolin Ke <guolin.ke@outlook.com>

src/network/socket_wrapper.hpp

@@ -27,7 +27,6 @@
 
 #include <arpa/inet.h>
 #include <fcntl.h>
-#include <ifaddrs.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
@@ -36,6 +35,13 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+// ifaddrs.h is not available on Solaris 10
+#if (defined(sun) || defined(__sun)) && (defined(__SVR4) || defined(__svr4__))
+  #include "ifaddrs_patch.h"
+#else
+  #include <ifaddrs.h>
+#endif
+
 #endif  // defined(_WIN32)
 
 #ifdef _MSC_VER