Update for Houdini 17.0

Release 7.1.0

1. Updated for Houdini 17.0.

2. New expression functions added:

    float arclenD(string surface_node, float prim_num, float ustart, float ustop, float divs)
    string chopnames(string CHOP)
    float contextoption(string token)
    string contextoptions(string token)
    float hascontextoption(string token)
    string lopinputprim(string lop_path, float input_index)
    string lopinputprims(string lop_path, float input_index)
    string loplastmodifiedprim(string lop_path)
    string loplastmodifiedprims(string lop_path)
    string topexp(string expression)

    Tip: to read about new functions quickly, copy the list in empty
    Sublime Text document, set HScript syntax and check documentation helpcards.

3. Older expressions that is now highlighted and documented:

    float dopgroupismutual(string dop, string group)
    float raw()
    string seampoints(string surface_node, float whichside)

4. Commands highlighted in syntax:

    animeditor
    chautoselect
    imgsave
    kinconvert
    matrman
    matupdateref
    rexport
    shopconvert
    system