Add .x86_64 and _amd64 suffixes to .rpm and .debs

Also:
* update README documentation
* correct postinst scripts for deb and rpm
* add lib64/ to link_directories (needed for CentOS and others)
* remove a redundant "rdc" from the package names
* rearrange the package names to conform to convention
For example:
rdc-server_1.0.0.0.local-build-0-c3187fb-dirty_amd64.deb
rdc-server_1.0.0.0.local-build-0-c3187fb-dirty.x86_64.rpm

* fix issues that result from having, in essence, 2 different
  install prefixes, 1 for the client and 1 for the server.

Change-Id: I88f0e1b8b72df2793c35ed71534afd91142da012

src/DEBIAN_postinst.in

@@ -1,6 +1,6 @@
 #/bin/bash
 
-RDC_LIB_DIR=@RDC_CLIENT_ROOT_PATH@rdc/lib
+RDC_LIB_DIR=/opt/rocm/rdc/lib
 
 # This will return 0 if an id is created and non-zero if
 # it already exists

src/RPM_rpm_post.in

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-RDC_LIB_DIR=@RDC_CLIENT_ROOT_PATH@/rdc/lib
+RDC_LIB_DIR=/opt/rocm/rdc/lib
 do_create_rdc_user() {
     useradd -r -s /bin/nologin rdc
 }