DALiuGE Lowpass Components

This initial release provides several basic DAiuGE signal processing components. Filters Lowpass filters built with several libraries Numpy - pointwise convolution Numpy - FFT convolution FFTW PyCuda Generators Basic random signal generator Hann window generator Gaussian noise injector Utility Normalised cross-correlation calculator CI currently fails due to the pycuda dependency, tests pass locally however.本次首次发布提供若干基础DAiuGE信号处理组件。 滤波器 基于多类库构建的低通滤波器： Numpy——逐点卷积 Numpy——快速傅里叶变换（FFT）卷积 FFTW PyCuda 生成器 基础随机信号生成器 汉宁窗生成器 高斯噪声注入器 实用工具 归一化互相关计算器 当前由于PyCuda依赖项问题，持续集成（Continuous Integration, CI）测试未能通过，但本地测试可正常运行。