Optimized drawPiece and importPiece

Changes:
-drawPiece now adjusts its looping boundaries based on the type of tetromino it is drawing. Further optimizations might find a simple way to take into account the type and orientation to reduce the amount of looping required.
-Calls to drawPiece were also modified to keep the active piece on the LED array for a slightly larger fraction of each runcycle (close to 100%).
-importPiece optimized by moving if statements outside of the loops and replacing fillArray with two calls to drawRectangle, sacrificing some succinctness of code for efficiency.

Notices: (unchanged from last push)
-This  version of the code includes a global 3D array to temporarily skirt the development complications of a potentially necessary tetrominoes.h, which would just include that 3D array.
-This version of the code includes a placeholder menu. It also includes test input handling for Windows, which can be enabled in Windows by de-commenting everything below the two "/*Windows:*/" tags and commenting everything below the "/*Linux:*/" tags, as well as de-commenting the body of getLeftInput(). The keybindings are as follows:
A - shift left
D - shift right
S - "soft drop" (shift one space downward)
W - "hard drop" (shift all the way downward and spawn a new piece)
Q - spin counter-clockwise
E - spin clockwise

To do:
-Overhaul of checkLines (which is not presently called) for line clearing and scoring.
-Managing collisions detected when the player rotates the piece ("wall kicks", etc.)
-Try to simplify the body of tetris() and shorten parameter lists.
-Consider solutions to inconsistent response to input. If the game runs faster on the Raspberry Pi with everything running than in Code::Blocks, as is expected, then dropTimer should be higher (even high enough to necessitate sleep functions) and this shouldn't be a problem. Regardless, consider worst-case solutions, one of which would be moving getLeftInput to the end of each input path (including input==0) except for automatically triggered soft drops; this may give a more consistent response to input at low values of dropTimer, but introduce an overall input lag.