setGlobalFloatArray can lead to a crash

[eitomurakami]

Calling setGlobalFloatArray with a large array (1000+ elements) every audio block (~10 ms) can crash ChucK.
Observed in RayTone (Chunity) and Pandora (C++).

[gewang]

added internal / audio-thread-call friendly global array setters in ffa7f1c

t_CKBOOL set_global_int_array( const std::string & name, t_CKINT arrayValues[], t_CKUINT numValues );
t_CKBOOL set_global_int_array_value( const std::string & name, t_CKUINT index, t_CKINT value );
t_CKBOOL set_global_float_array( const std::string & name, t_CKFLOAT arrayValues[], t_CKUINT numValues );
t_CKBOOL set_global_float_array_value( const std::string & name, t_CKUINT index, t_CKFLOAT value );

[gewang]

also, added check for globals array access for valid global variable names in ae90d57 (previously accessing an invalid name, or accessing it before the variable is created in the VM leads to a crash)

[gewang]

both issues (in RayTone and Pandora respectively) appear to be resolved with the above commits