newer_version_startup_check() compares gstate.client_version_check_url to nvc_config.client_version_check_url. If different, it clears gstate.newer_version and updates gstate.client_version_check_url.
Emphasize this difference by changing NVC_CONFIG struct member new_version_text to new_version_name.
Fix a bug I introduced in release_brand.sh script.
If nvc_config.cml file is absent, use default values.
Branded installers can create or replace this file to customize these values.
Standard (unbranded) BOINC installers should either delete the file or create or replace it with one containing default values.