[Taler] documentation corrections and taler-exchange-secmod-* configuration

[Slack Coder]

Hi,

I've noticed some small issues while integrating the Taler Exchange up on Slackware.

Best Regards,

Slack Coder

### Taler Exchange Operator Manual documentation

"taler-exchange-db: group for all Taler users with direct database access, specifically taler-exchange-httpd, taler-exchange-wire, taler-exchange-closer and taler-exchange-aggregator."

should be use 'taler-exchange-wirewatch' instead:

"taler-exchange-db: group for all Taler users with direct database access, specifically taler-exchange-httpd, taler-exchange-wirewatch, taler-exchange-closer and taler-exchange-aggregator."

### taler-exchange-secmod-* configuration

It appears the secmod commands do not respect the TALER_DATA_HOME and TALER_RUNTIME_DIR configuration parameters.  Below are snippets from relevant files.

```/etc/taler/taler.conf

[taler]
CURRENCY = KUDOS
CURRENCY_ROUND_UNIT = KUDOS:0.01

TALER_HOME=/var/lib/taler
TALER_DATA_HOME=/var/lib/taler
TALER_CACHE_HOME=/var/cache/taler
TALER_RUNTIME_DIR=/run/taler

[...]

```

```/etc/rc.d/rc.taler-exchange

# FIXME: taler-exchange-secmod commands do not respect 'TALER_DATA_HOME' configuration.
(cd /var/lib/taler
  if [ ! -d .local ]; then
    mkdir -p .local/share &&
    cd .local/share &&
    ln -fs ../.. taler
  fi
)

# FIXME: taler-exchange-secmod commands do not respect 'TALER_RUNTIME_DIR' configuration.
(cd /tmp
  rm -fr taler-system-runtime
  mkdir -p /run/taler &&
  chown root:taler /run/taler &&
  chmod g+rwX /run/taler &&
  ln -fs /run/taler taler-system-runtime)

[...]

start() {
  echo "Starting Taler Exchange"

[...]
  daemon \
    --name=taler-exchange-secmod-cs \
    --user=taler-exchange-secmod-cs \
    --pidfiles=/run/taler \
    --output=/var/log/taler/taler-exchange-secmod-cs.log \
    --env="USERPROFILE=/var/lib/taler" \
    --env="TALER_DATA_HOME=/var/lib/taler" \
    --env="TALER_CACHE_HOME=/var/cache/taler" \
    --env="TALER_RUNTIME_DIR=/run/taler" \
    -- taler-exchange-secmod-cs -c /etc/taler/taler.conf

  daemon \
    --name=taler-exchange-secmod-rsa \
    --user=taler-exchange-secmod-rsa \
    --pidfiles=/run/taler \
    --output=/var/log/taler/taler-exchange-secmod-rsa.log \
    --env="USERPROFILE=/var/lib/taler" \
    --env="TALER_DATA_HOME=/var/lib/taler" \
    --env="TALER_CACHE_HOME=/var/cache/taler" \
    --env="TALER_RUNTIME_DIR=/run/taler" \
    -- taler-exchange-secmod-rsa -c /etc/taler/taler.conf

  daemon \
    --name=taler-exchange-secmod-eddsa \
    --user=taler-exchange-secmod-eddsa \
    --pidfiles=/run/taler \
    --output=/var/log/taler/taler-exchange-secmod-eddsa.log \
    --env="USERPROFILE=/var/lib/taler" \
    --env="TALER_DATA_HOME=/var/lib/taler" \
    --env="TALER_CACHE_HOME=/var/cache/taler" \
    --env="TALER_RUNTIME_DIR=/run/taler" \
    -- taler-exchange-secmod-eddsa -c /etc/taler/taler.conf
[...]
}

[...]

```