Version bump for release 0.1.7 RC 1

This adds support for declaring predicates as placeholders through the
“#external” directive in the input language of clingo.

Placeholders are not subject to completion. This prevents predicates
that represent instance-specific facts from being assumed as universally
false by default negation when translating an encoding.

This stretches clingo’s usual syntax a bit in order to make the
implementation lightweight. In order to declare a predicate with a
specific arity as a placeholder, the following statement needs to be
added to the input program:

CHANGELOG.md

@@ -1,18 +1,14 @@
 # Change Log
 
-## 0.1.7 RC 2 (2018-04-06)
+## 0.1.7 (2018-04-05)
 
-### Features
+Features:
 
 * support for declaring placeholders with the `#external` directive
 
-### Internal
-
-* drops Boost dependency in favor of the header-only command-line option library [cxxopts](https://github.com/jarro2783/cxxopts)
-
 ## 0.1.6 (2017-06-12)
 
-### Features
+Features:
 
 * unique IDs for all variables (user-defined variables are renamed)
 * support for hiding predicates from completed output by using `#show` statements
@@ -20,7 +16,7 @@
 * command-line option `--parentheses` to fully parenthesize the output
 * adds multiple example instances for experimenting
 
-### Bug Fixes
+Bug Fixes:
 
 * adds missing error message when attempting to read inaccessible file
 * removes unnecessary parentheses after simplification
@@ -28,52 +24,52 @@
 
 ## 0.1.5 (2017-05-04)
 
-### Bug Fixes
+Bug Fixes:
 
 * fixes lost signs with negated 0-ary predicates
 
 ## 0.1.4 (2017-04-12)
 
-### Features
+Features:
 
 * completion of input programs (optional)
 * command-line option `--complete` to turn on completion
 
 ## 0.1.3 (2017-03-30)
 
-### Features
+Features:
 
 * support for anonymous variables
 
-### Bug Fixes
+Bug Fixes:
 
 * fixes incorrectly simplified rules with comparisons
 * fixes misleading error message concerning negated, unsupported body literals
 
 ## 0.1.2 (2017-03-23)
 
-### Features
+Features:
 
 * simplification of output formulas (optional)
 * command-line option `--simplify` to turn on simplification
 
-### Bug Fixes
+Bug Fixes:
 
 * fixes incorrectly translated choice rules with multiple elements in the head aggregate
 
-### Internal
+Internal:
 
 * explicit syntax tree representation for first-order formulas
 
 ## 0.1.1 (2017-03-06)
 
-### Features
+Features:
 
 * support for choice rules (without guards)
 
 ## 0.1.0 (2016-11-24)
 
-### Features
+Features:
 
 * initial support for translating rules in *Essential Gringo* (excluding aggregates) to first-order logic formulas
 * command-line option `--color` to autodetect, enable, or disable color output

app/main.cpp

@@ -70,7 +70,7 @@ int main(int argc, char **argv)
 
 	if (version)
 	{
-		std::cout << "anthem version 0.1.7-rc.2" << std::endl;
+		std::cout << "anthem version 0.1.7-rc.1" << std::endl;
 		return EXIT_SUCCESS;
 	}