The `make install` script, which most users would run via `sudo` to install into `/usr/local`, will use the current umask of the root user when creating certain files and directories. If one uses a restrictive umask by default (e.g. `umask 077`), this means that only the root user will be able to use the full Bitcoin package.

**Expected behavior**

The install script creates all directories and files, including man pages, etc., with permissions `644` / `755`.

**Actual behavior**

Certain folders are created using the default umask, e.g.:

- /usr/local/share/man/man1/
- /usr/local/lib/pkgconfig/
- [...]

This means that only root can access files in these folders and other users won't be able to read the man pages (for example).

**To reproduce**

```bash
$ ./autogen.sh
$ make
$ sudo -iu root
% umask 077
% make install
```

**System information**

OS: Linux
bitcoind version: HEAD
{
    node.chain = node.init->makeChain();
    return true;
}
bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
{
    const ArgsManager& args = *Assert(node.args);
    const CChainParams& chainparams = Params();
    auto opt_max_upload = ParseByteUnits(args.GetArg("-maxuploadtarget", DEFAULT_MAX_UPLOAD_TARGET), ByteUnit::M);
    if (!opt_max_upload) {
        return InitError(strprintf(_("Unable to parse -maxuploadtarget: '%s'"), args.GetArg("-maxuploadtarget", "")));
    }
    
    if (!CreatePidFile(args)) {
        
        return false;
    }
    if (!init::StartLogging(args)) {
        
        return false;
    }
    LogPrintf("Using at most %i automatic connections (%i file descriptors available)\n", nMaxConnections, nFD);
    
    if (args.IsArgSet("-datadir") && !args.GetPathArg("-datadir").is_absolute()) {
        LogPrintf("Warning: relative datadir option '%s' specified, which will be interpreted relative to the " 
                  "current working directory '%s'. This is fragile, because if bitcoin is started in the future "