config: add support for config value formatting flags

There are two basic groups of formatting flags (32 bits):
  - common ones applicable for all config value types (lower 16 bits)
  - type-related formatting flags (higher 16 bits)

With this patch, we initially support four new flags that
modify the the way the config value is displayed:

  Common flags:
  =============

  DM_CONFIG_VALUE_FMT_COMMON_ARRAY - causes array config values
    to be enclosed in "[ ]" even if there's only one item
    (previously, there was no way to recognize an array with one
     item and scalar value, hence array values with one member
     were always displayed without "[ ]" which libdm accepted
     when reading, but it may have been misleading for users)

  DM_CONFIG_VALUE_FMT_COMMON_EXTRA_SPACE - causes extra spaces to
    be inserted in "key = value" (or key = [ value, value, ... ] in
    case of arrays), compared to "key=value" seen on output before.
    This makes the output more readable for users.

  Type-related flags:
  ===================

  DM_CONFIG_VALUE_FMT_INT_OCTAL - prints integers in octal form with
    "0" as a prefix (libdm's config reading code can handle this via
    strtol just fine so it's properly recognized as number in octal
    form already if there's "0" used as prefix)

  DM_CONFIG_VALUE_FMT_STRING_NO_QUOTES - makes it possible to print
    strings without enclosing " "

This patch also adds dm_config_value_set_format_flags and
dm_config_value_get_format_flags functions to set and get
these formatting flags.

1 files changed, 2 insertions, 0 deletions

diff --git a/libdm/.exported_symbols.DM_1_02_100 b/libdm/.exported_symbols.DM_1_02_100
new file mode 100644
index 000000000..00d7d5b10
--- /dev/null
+++ b/libdm/.exported_symbols.DM_1_02_100
@@ -0,0 +1,2 @@
+dm_config_value_set_format_flags
+dm_config_value_get_format_flags