Changed a few things

- Bumped to 0.15.0
- Add boot script
- Change variable definition syntax, using a = to distinguish more cleary between identifier and value
- Variables initial values are evaluated on first use instead of at parsing time
- Error on variable redefinition. Means you should make sure to load saves after your scripts.
- Improve string parsing, support for escape codes
- Remove support for number literals with empty decimal part (42. for 42.0) as there's no distinction in Anselme and it conflicts with .function call suffix
- Changed priority of : pair operator
- Add type type, and type annotations to variables and function parameters
- Change Lua function system to use regular Anselme functions
  - Defining a function from Lua is now way simpler and require providing a full Anselme function signature
- Change Anselme function system
  - Dynamic dispatch, based on arity, type annotation and parameter names. Will select the most specific function at runtime.
  - Define way to overload most operators
  - Allow custom type to text formatters
  - Allow assignment to custom functions
  - Index operator ( renamed to ()
  - Functions with parameters each have their own private namespace (scoping ersatz)
  - Internal: "custom"-mode operators now have their own expression AST type instead of cluttering the function system
- Remove static type checker as it is barely useful with new function system. May or may not rewrite one in the future.
- Improve error messages here and there
- Internal: cleaning

test/tests/resume from paragraph with nested choice.lua

@@ -1,7 +1,4 @@
 local _={}
-_[121]={}
-_[120]={}
-_[119]={}
 _[118]={}
 _[117]={}
 _[116]={}
@@ -34,15 +31,15 @@ _[90]={}
 _[89]={}
 _[88]={}
 _[87]={}
-_[86]={data="c",tags=_[121]}
-_[85]={data="b",tags=_[120]}
-_[84]={data="a",tags=_[119]}
-_[83]={data="-> aa",tags=_[118]}
-_[82]={data="ab",tags=_[117]}
-_[81]={data="aa",tags=_[116]}
-_[80]={data="-> aa",tags=_[115]}
-_[79]={data="ab",tags=_[114]}
-_[78]={data="aa",tags=_[113]}
+_[86]={data="c",tags=_[118]}
+_[85]={data="b",tags=_[117]}
+_[84]={data="a",tags=_[116]}
+_[83]={data="-> aa",tags=_[115]}
+_[82]={data="ab",tags=_[114]}
+_[81]={data="aa",tags=_[113]}
+_[80]={data="-> aa",tags=_[112]}
+_[79]={data="ab",tags=_[112]}
+_[78]={data="aa",tags=_[112]}
 _[77]={data="-> a",tags=_[112]}
 _[76]={data="c",tags=_[111]}
 _[75]={data="b",tags=_[110]}
@@ -222,10 +219,10 @@ return {_[1],_[2],_[3],_[4],_[5],_[6],_[7],_[8],_[9],_[10],_[11],_[12],_[13],_[1
     } } }
 { "choice", { {
       data = "aa",
-      tags = {}
+      tags = <1>{}
     }, {
       data = "ab",
-      tags = {}
+      tags = <table 1>
     } } }
 { "text", { {
       data = "-> aa",