printers FEATURE submodule print

Also some refactorization included,
which consists mostly of removing
compiled import structure as it is
not needed in a compiled module and
is not even really viable because
of submodules.
diff --git a/src/parser_yang.c b/src/parser_yang.c
index 47833ab..94cce2c 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -4446,6 +4446,7 @@
     *context = calloc(1, sizeof **context);
     LY_CHECK_ERR_RET(!(*context), LOGMEM(ly_ctx), LY_EMEM);
     (*context)->format = LYS_IN_YANG;
+    (*context)->main_mod = main_ctx->main_mod;
     (*context)->ctx = ly_ctx;
     (*context)->pos_type = LY_VLOG_LINE;
     (*context)->line = 1;
@@ -4512,6 +4513,7 @@
     *context = calloc(1, sizeof **context);
     LY_CHECK_ERR_RET(!(*context), LOGMEM(mod->ctx), LY_EMEM);
     (*context)->format = LYS_IN_YANG;
+    (*context)->main_mod = mod;
     (*context)->ctx = mod->ctx;
     (*context)->pos_type = LY_VLOG_LINE;
     (*context)->line = 1;