[gimp] libgimpbase: update gimp_unit_get_digits() description.

[Jehan Pagès <jehanp src gnome org>]

commit 7a330dcf6a05675b4c83b0ff6c5b9947b5fffc60
Author: Jehan <jehan girinstud io>
Date:   Thu Jan 19 15:01:54 2017 +0100

    libgimpbase: update gimp_unit_get_digits() description.
    
    Digit accuracy being "approximately the same as an inch with 2 digits"
    is only true for built-in units, not user-defined ones.

 libgimpbase/gimpunit.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/libgimpbase/gimpunit.c b/libgimpbase/gimpunit.c
index 6790b07..8daa4dc 100644
--- a/libgimpbase/gimpunit.c
+++ b/libgimpbase/gimpunit.c
@@ -239,8 +239,9 @@ gimp_unit_get_factor (GimpUnit unit)
  * gimp_unit_get_digits:
  * @unit: The unit you want to know the digits.
  *
- * Returns the number of digits an entry field should provide to get
- * approximately the same accuracy as an inch input field with two digits.
+ * Returns the number of digits set for @unit.
+ * Built-in units' accuracy is approximately the same as an inch with
+ * two digits. User-defined units can suggest a different accuracy.
  *
  * Returns 0 for @unit == GIMP_UNIT_PIXEL.
  *