Fix 1e parsing

Fix 1e5, 1e-5 evaluated as Infinity (https://github.com/HaxeFoundation/hscript/pull/132)

TestHScript.hx

@@ -33,6 +33,10 @@ class TestHScript extends TestCase {
 		assertScript("- 123",-123);
 		assertScript("1.546",1.546);
 		assertScript(".545",.545);
+		assertScript("1e5",100000);
+		assertScript("1.2e2",120);
+		assertScript("100e-2",1);
+		assertScript("1.2e-1",0.12);
 		assertScript("'bla'","bla");
 		assertScript("null",null);
 		assertScript("true",true);

hscript/Parser.hx

@@ -1943,6 +1943,8 @@ class Parser {
 						}
 						if( pow == null )
 							invalidChar(char);
+						if( exp == 0 )
+							exp = 10;
 						return TConst(CFloat((Math.pow(10, pow) / exp) * n * 10));
 					case ".".code:
 						if( exp > 0 ) {