v2.0.2

The following changes/additions have been made to the library

• feat: created GUI containers for better internalization
• feat: changed containers for a single Drop Zone object, intended for file-dropping
• feat: gave the ability to authorize multiple file extensions in drop zones

• fix: internalized cursor state detection (no more external focus management)
• fix: fixed textboxes' colors when selected, no more extremely darkened colors
• fix: fixed panels' size attributes leading to unsure results to the screen
• fix: removed null output file-path on file-droppers