Use global variable definition into configuration.

As reported in issue #52, the automatically generated configuration
exploits Bash `declare` to define variable. When
`pgenv_configuration_load` does `source` the configuration file,
declared variables are locally scoped as reported in the `declare`
help:

    When used in a function, `declare' makes NAMEs local, as with the `local'
    command.  The `-g' option suppresses this behavior.

Therefore every `declare` statement has to be prefix with
`-g`. Unluckily it seems that the counterpart `declare`, used to print
out the variable in `pgenv_configuration_write` does not outputs the
`-g` flag, probably because at that time the variable is already
global.
Therefore, before hitting the configuration file, I append the `-g`
option to `declare` with a regexp.

This `-g` works on Bash 4.4 and 5 on my Linux machines.

Bumped version number.

Close #52

bin/pgenv

@@ -2,7 +2,7 @@
 #
 # VERSION
 #
-PGENV_VERSION="1.2.1"
+PGENV_VERSION="1.2.2"
 
 # https://stackoverflow.com/a/19622569/79202
 trap 'exit' ERR
@@ -619,7 +619,9 @@ pgenv_configuration_write_variable(){
 
     # if no value supplied, put a comment
     if [[ "$name" =~ _OPTIONS$ ]]; then
-        typeset -p "${name}" >> "$file"
+        # declare has no way to output a global variable
+        # that is then needed when reloading configuration !
+        declare  -p "${name}" | sed 's/declare/declare -g /' >> "$file"
     else
         if [ -z "$value" ]; then
             echo -n "#" >> "$file"