Add Json importer (#46)

add boost-json to dependencies

doc/function/new_card.txt

@@ -12,6 +12,7 @@ NOTE: you should use underscores instead of spaces in field names.
 --Parameters--
 ! Parameter	Type							Description
 | @input@	[[type:map]] of field names to field values		Field values to set
+| @ignore_field_not_found@	[[type:boolean]]		Optional. If set to true, key/value pairs that don't correspond to a card field will be ignored instead of throwing.
 
 --Examples--
 > # Create a new card

doc/type/field.txt

@@ -43,10 +43,10 @@ Fields are part of the [[file:style triangle]]:
 | @card list name@	[[type:localized string]]		field name	Alternate name to use for the card list, for example an abbreviation.
 | @card list alignment@	[[type:alignment]]	@left@		Alignment of the card list column.
 | @sort script@		[[type:script]]		 		Alternate way to sort the card list when using this column to sort the list.
-| @construction script@		[[type:script]]		 		Script applied to the value given when creating a card with the new_card function.
+| @import script@		[[type:script]]		 		Script applied to the value given when creating a card with the new_card function. The script may return a map from field names to values.
 			 			 		For example, the pt field should not be initialized directly, since it is a combination of the power field and toughness field.
 			 			 		So if a value is given for pt, it must be redirected to power and toughness like so: {split := split_text(value, match:"/"); [power:split[0], toughness:split[1]]}.
-			 			 		The script must return a map from field names to values. Use the make_map function to dynamically create maps.
+			 			 		Use the make_map function to dynamically create maps.
 
 The @type@ determines what values of this field contain:
 ! Type			Values contain								Displayed as

doc/type/game.txt

@@ -33,7 +33,7 @@ Such a package contains a [[file:format|data file]] called <tt>game</tt> that ha
 | @default set style@		[[type:indexmap]] of [[type:style]]s	 		Default style for the set fields, can be overridden by the stylesheet.
 | @card fields@			[[type:list]] of [[type:field]]s	 		Fields for each card.
 | @card list color script@	[[type:script]]				from fields	Script that determines the color of an item in the card list. <br/>If not set uses the @card list colors@ property of the first card field that has it.
-| @construction script@		[[type:script]]				 	Script that is applied as the last step in the creation of a card in the new_card function. Must return a map from field names to values. Use the make_map function to dynamically create maps.
+| @import script@		[[type:script]]				 	Script that is applied as the last step in the creation of a card in the new_card function. Must return a map from field names to values. Use the make_map function to dynamically create maps.
 | @statistics dimensions@	[[type:list]] of [[type:statistics dimension]]s		from fields	Dimensions for statistics, a dimension is roughly the same as an axis. <br/>By default all card fields with 'show statistics' set to true are used.
 | @statistics categories@	[[type:list]] of [[type:statistics category]]s		from dimensions	DOC_MSE_VERSION: not used since 0.3.6
 				 					 		Choices shown on the statistics panel. <br/>By default all statistics dimensions are used.

doc/type/locale.txt

@@ -61,5 +61,5 @@ To translate the MSE user interface:
 * Add new keys for game, stylesheet or symbol font specific keys as described above.
 * Save the file, select the new locale from Edit->Preferences.
 * Restart MSE, and make sure everything looks right.
-* Submit the new locale to the [[http://magicseteditor.sourceforge.net/forum/7|MSE forum].
+* Submit the new locale as a pull request to the [[https://github.com/MagicSetEditorPacks/Full-Magic-Pack|Full-Magic-Pack repository].
 * Maintain the locale when new versions of MSE come out. A new version may have new user interface items and therefore new keys.